[424B5] Simmons First National Corp Prospectus Supplement (Debt Securities)

Rhea-AI Filing Summary

Simmons First National Corporation is offering fixed-to-floating rate subordinated notes due 2035, with the floating rate expected to be Three-Month Term SOFR plus a spread. The company intends to use proceeds, together with cash on hand if needed, to repay in full the $330 million principal amount of its 2028 Notes on October 1, 2025 and for general corporate purposes. The indenture governing the Notes does not limit the amount of additional indebtedness the company or its subsidiaries may incur.

As of June 30, 2025, on a consolidated basis Simmons reported approximately $23.1 billion of total liabilities, including about $21.8 billion of deposit liabilities, and approximately $366.4 million of outstanding principal and accrued interest of subordinated debentures that rank equally with the Notes (the Spirit Notes component of $37.0 million was redeemed in full on July 31, 2025). The prospectus supplement describes interest calculation conventions for the fixed and floating periods, tax and withholding rules for non-U.S. holders, and other customary terms and risk factors incorporated by reference from Simmons’ SEC filings.

Positive

• Proceeds targeted to repay $330 million 2028 Notes, extending subordinated debt maturity and reducing near-term refinancing pressure
• Detailed tax and withholding guidance for non-U.S. holders provided, aiding investor tax planning

Negative

• Indenture does not limit additional indebtedness, permitting the company or subsidiaries to incur more debt that could dilute claimants
• Notes are subordinated and rank behind Senior Indebtedness, exposing holders to higher credit risk in default
• Benchmark fallback language involves subjective determinations (Benchmark Transition Event and Replacement Conforming Changes) that may adversely affect interest payouts

Insights

Financial Analyst

TL;DR: Issuance repays near-term subordinated debt, modestly extends maturity profile but leaves room for additional indebtedness.

The offering appears structured to refinance the $330 million 2028 subordinated notes, which lengthens the company’s subordinate debt maturity and preserves liquidity by using market financing instead of operating cash. The pro forma and as-adjusted condensed balances shown indicate management anticipates modest balance sheet changes after the transactions described. Key metrics include consolidated liabilities of ~$23.1 billion and deposit liabilities of ~$21.8 billion as of June 30, 2025, which underscore the bank’s deposit-funded balance sheet. Investors should note the prospectus discloses no contractual limit on future indebtedness under the Indenture.

Risk Analyst

TL;DR: Material risk from subordination, subjective benchmark determinations, and open capacity to incur more debt.

The Indenture’s lack of a cap on additional indebtedness and the subordinated status of the Notes mean holders rank behind Senior Indebtedness and payments may be restricted if Senior Indebtedness is unpaid. The prospectus also calls out potentially subjective determinations regarding Benchmark Transition Events and Benchmark Replacement Conforming Changes, which could affect interest payouts. These are material contract-level risks that could adversely affect noteholders in stressed scenarios.

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The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus do not constitute an offer to sell these securities and we are not soliciting offers to buy these securities in any jurisdiction where the offer or sale is not permitted.

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-279502

SUBJECT TO COMPLETION, DATED SEPTEMBER 9, 2025

PRELIMINARY PROSPECTUS SUPPLEMENT

(To Prospectus dated May 17, 2024)

$

Simmons First National Corporation

% Fixed-to-Floating Rate Subordinated Notes due 2035

We are offering $   aggregate principal amount of    % fixed-to-floating rate subordinated notes due 2035 (the “Notes”) pursuant to this prospectus supplement and the accompanying prospectus. The Notes will be offered in minimum denominations of $1,000 and integral multiples of $1,000 in excess thereof. The Notes will mature on    , 2035 (the “Maturity Date”). From and including the date of original issuance to, but excluding,    , 2030 or the date of earlier redemption (the “fixed rate period”), the Notes will bear interest at an initial rate of    % per annum, payable semi-annually in arrears on    and    of each year, commencing on    , 2026. The last interest payment date for the fixed rate period will be    , 2030. From and including    , 2030 to, but excluding, the Maturity Date or the date of earlier redemption (the “floating rate period”), the Notes will bear interest at a floating rate per annum equal to a benchmark rate (which is expected to be Three-Month Term SOFR (as defined herein)), plus    basis points, payable quarterly in arrears on    ,    ,    and    of each year, commencing on    , 2031. Notwithstanding the foregoing, in the event that the Three-Month Term SOFR is less than zero, the Three-Month Term SOFR shall be deemed to be zero.

We may, at our option, beginning with the interest payment date of    , 2030 and on any interest payment date thereafter, redeem the Notes, in whole or in part. The Notes will not otherwise be redeemable by us prior to maturity, unless certain events occur, as described under “Description of the Notes — Redemption” in this prospectus supplement. The redemption price for any redemption is 100% of the principal amount of the Notes, plus accrued and unpaid interest thereon to, but excluding, the date of redemption. Any early redemption of the Notes will be subject to the receipt of the approval of the Board of Governors of the Federal Reserve System (the “Federal Reserve”) to the extent then required under applicable laws or regulations, including capital regulations.

The Notes will be unsecured subordinated obligations, will rank pari passu, or equally, with all of our future unsecured subordinated debt and will be junior to all of our existing and future senior debt. The Notes will be structurally subordinated to all existing and future liabilities of our subsidiaries and will be effectively subordinated to our existing and future secured indebtedness. There will be no sinking fund for the Notes. The Notes will be obligations of Simmons First National Corporation only and will not be obligations of, and will not be guaranteed by, any of Simmons First National Corporation’s subsidiaries. For a more detailed description of the Notes, see “Description of the Notes.”

Prior to this offering, there has been no public market for the Notes. The Notes will not be listed on any securities exchange or included in any automated quotation system.

The Notes are not savings accounts, deposits or other obligations of any of our bank or non-bank subsidiaries, and are not insured or guaranteed by the Federal Deposit Insurance Corporation (the “FDIC”) or any other governmental agency. The Notes are ineligible as collateral for a loan or extension of credit from Simmons First National Corporation or any of its subsidiaries. None of the U.S. Securities and Exchange Commission (the “SEC”), any state securities commission or banking agency, the FDIC, the Board of Governors of the Federal Reserve or any other regulatory body has approved or disapproved of the Notes or passed upon the accuracy or adequacy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

Investing in the Notes involves risks. Before investing in the Notes, potential purchasers of the Notes should consider the information set forth in the “Risk Factors” section beginning on page S-11, in our Annual Report on Form 10-K for the year ended December 31, 2024 and in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2025, which are incorporated herein by reference.

		Per Note				Total
Public offering price(1)		$				$
Underwriting discounts and commissions(2)		$				$
Proceeds, before expenses, to us		$				$

⁽¹⁾  Plus accrued interest, if any, from the original issue date.

⁽²⁾  The underwriters will also be reimbursed for certain expenses incurred in this offering. See “Underwriting” for details.

The underwriters expect to deliver the Notes to purchasers in book-entry form through the facilities of The Depository Trust Company (“DTC”), against payment therefor in immediately available funds, on or about     , 2025, which is the third business day following the date of pricing the Notes (such settlement being referred to as “T+3”). See “Underwriting” for details.

Joint Book-Running Managers

Keefe, Bruyette & Woods     A Stifel Company Morgan Stanley

The date of this prospectus supplement is September    , 2025.

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TABLE OF CONTENTS

Prospectus Supplement

		Page
About This Prospectus Supplement and the Accompanying Prospectus			S-ii
Where You Can Find More Information			S-1
Incorporation by Reference			S-2
Cautionary Note Regarding Forward-Looking Statements			S-3
Summary			S-5
Risk Factors			S-11
Use of Proceeds			S-19
Unaudited Pro Forma Financial Information			S-20
Capitalization			S-22
Description of Notes			S-23
Certain ERISA Considerations			S-43
Material U.S. Federal Income Tax Considerations			S-45
Underwriting			S-50
Legal Matters			S-53
Experts			S-53

Prospectus

		Page
About This Prospectus			1
Where You Can Find More Information			2
The Company			3
Risk Factors			4
Use of Proceeds			4
Legal Matters			4
Experts			4

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ABOUT THIS PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS

This document is composed of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering, the risks of investing in the Notes and certain other matters relating to us and our financial condition. This prospectus supplement also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part of this document is the accompanying prospectus, dated May 17, 2024, which is included as part of our automatic shelf registration statement on Form S-3ASR (File No. 333-279502). That registration statement and the accompanying prospectus provide more general information about securities that we may offer from time to time, some of which may not apply to this offering. It is important for you to read and consider carefully all information contained or incorporated by reference in this prospectus supplement, the accompanying prospectus and any permitted free writing prospectuses we have authorized for use with respect to this offering before investing in our securities. See “Where You Can Find More Information” and “Incorporation by Reference” for additional information.

This prospectus supplement, or the information incorporated by reference in this prospectus supplement, may add, update or change information in the accompanying prospectus. If information in this prospectus supplement is inconsistent with the accompanying prospectus, this prospectus supplement will supersede the information in the accompanying prospectus.

In various places in this prospectus supplement and the accompanying prospectus, we refer you to sections of other documents for additional information by indicating the caption heading of the other sections. All cross-references in this prospectus supplement are to captions contained in this prospectus supplement and not in the accompanying prospectus, unless otherwise indicated.

In this prospectus supplement, unless otherwise required by the context, the terms “we,” “our,” “us,” “Simmons,” and the “Company,” refer to Simmons First National Corporation and, where appropriate, its consolidated subsidiaries, including its wholly-owned subsidiary bank, Simmons Bank.

Neither the Company nor the underwriters have authorized anyone to provide you with any information other than that contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or in any free writing prospectus prepared by or on behalf of the Company, or to which the Company has referred you. Neither the Company nor the underwriters take any responsibility for, or can provide any assurance as to the reliability of, any information that others may give you. If any information in this prospectus supplement is inconsistent with the accompanying prospectus or any document incorporated by reference in this prospectus supplement or the accompanying prospectus, you should rely on the information in this prospectus supplement. You should not assume that the information provided in this prospectus supplement, the accompanying prospectus or the documents incorporated by reference in this prospectus supplement and in the accompanying prospectus is accurate as of any date other than the date of this prospectus supplement or the date of the document in which that information is contained. Our business, financial condition, liquidity, results of operations and prospects may have changed since the date of any document in which such information is contained.

Neither the Company nor the underwriters are offering to sell nor seeking an offer to buy the Notes in any jurisdiction where such offers and sales are not permitted. The distribution of this prospectus supplement and the accompanying prospectus and the offering of the Notes in certain jurisdictions may be restricted by law.

Persons outside the United States who come into possession of this prospectus supplement and the accompanying prospectus must inform themselves about and observe any restrictions relating to the offering of the Notes and the distribution of this prospectus supplement and the accompanying prospectus outside the United States. This prospectus supplement and the accompanying prospectus do not constitute,

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and may not be used for or in connection with, an offer or solicitation by any person in any jurisdiction in which such offer or solicitation is not authorized or in which the person making such offer or solicitation is not authorized or is not qualified to do so or to any person to whom it is unlawful to make such offer or solicitation, and this prospectus supplement and the accompanying prospectus may not be delivered to any person to whom it is unlawful to make such offer or solicitation. See “Underwriting” in this prospectus supplement.

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WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our filings with the SEC are also available to the public through the SEC’s website at www.sec.gov.

Our annual, quarterly and current reports and any amendments to those reports are also available over the Internet on our website at www.simmonsbank.com. All internet addresses provided in this prospectus supplement or the accompanying prospectus are for informational purposes only and are not intended to be hyperlinks. In addition, the information on, or accessible through, our website, or any other website described herein, is not a part of, and is not incorporated or deemed to be incorporated by reference in, this prospectus supplement or the accompanying prospectus or other offering materials.

We have filed an automatic shelf registration statement (File No. 333-279502) with the SEC registering the offering of various securities of ours, including the securities offered by this prospectus supplement and the accompanying prospectus. This prospectus supplement and the accompanying prospectus are part of that registration statement. The registration statement may contain additional information that may be important to you. Statements contained in this prospectus supplement and the accompanying prospectus as to the contents of any contract or other document referred to, or incorporated by reference, in this prospectus supplement and the accompanying prospectus are not necessarily complete and, where that contract or document is an exhibit to the registration statement, each statement is qualified in all respects by the exhibit to which the reference relates. You may obtain from the SEC copies of the registration statement and the related exhibits that we filed with the SEC.

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INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus supplement and the accompanying prospectus the information that we have filed with the SEC. This means that we can disclose important information to you without actually including the specific information in this prospectus supplement by referring you to those documents filed separately with the SEC. The information incorporated by reference is an important part of this prospectus supplement and the accompanying prospectus. Information that we file later with the SEC will automatically update and replace information in this prospectus supplement and the accompanying prospectus and information previously filed with the SEC. In other words, in the case of any conflict or inconsistency between information in different documents, you should rely on the information in the document that was filed later.

We incorporate by reference the documents listed below and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 (the “Exchange Act”) (excluding in all cases any information furnished under Items 2.02 or 7.01 or exhibits furnished pursuant to Item 9.01 on any Current Report on Form 8-K or Amended Current Report on Form 8-K/A) after the date of this prospectus supplement and until the termination of the offering under this prospectus supplement:

• Our Annual Report on Form 10-K for the year ended December 31, 2024, filed on February 27, 2025;

• Our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2025, filed on May 8, 2025, and the quarter ended June  30, 2025, filed on August 5, 2025;

• Our Current Reports on Form 8-K filed with the SEC on March 10, 2025, May  8, 2025, July  23, 2025, July  25, 2025, August  4, 2025 and August 6, 2025; and

• Our revised definitive Proxy Statement on Schedule 14A filed on April 3, 2025 (solely to the extent incorporated by reference into Part III of our Annual Report on Form 10-K for the year ended December 31, 2024).

The information contained in this prospectus supplement and the accompanying prospectus will be updated and supplemented by the information contained in the filings we make with the SEC in the future and that are incorporated by reference into this prospectus supplement and the accompanying prospectus as described above. The information contained in those future filings will be considered to be part of this prospectus supplement and the accompanying prospectus and will automatically update and supersede, as appropriate, the information contained in this prospectus supplement and the accompanying prospectus and contained in the filings previously filed with the SEC that are incorporated by reference into this prospectus supplement and the accompanying prospectus.

Upon written or oral request, we will provide, without charge, to each person to whom a copy of this prospectus supplement and the accompanying prospectus is delivered a copy of the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. You may request a free copy of these filings by writing or telephoning us at the following address:

Simmons First National Corporation

P.O. Box 7009

Pine Bluff, Arkansas 71611

Attention: Ed Bilek

Telephone: (870) 541-1000

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

Certain statements contained in this prospectus supplement and the accompanying prospectus, including any information included or incorporated by reference into this prospectus supplement and the accompanying prospectus, may constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 (the “Reform Act”). These forward-looking statements may be identified by reference to a future period(s) or by the use of forward-looking terminology, such as “anticipate,” “believe,” “budget,” “contemplate,” “continue,” “estimate,” “expect,” “foresee,” “intend,” “indicate,” “likely,” “target,” “plan,” “positions,” “prospects,” “project,” “predict,” or “potential,” by future conditional verbs such as “could,” “may,” “might,” “should,” “will,” or “would,” by variations of such words, or by similar expressions. These forward-looking statements include, without limitation, those relating to the Company’s redemption of the 2028 Notes (as defined herein), the Investment Securities Transaction (as defined herein) (including the pro forma financial impacts and benefits thereof), future growth, business strategies, product development, acquisitions and their expected benefits, revenue, expenses, assets, asset quality, profitability, earnings, accretion, dividends, customer service, lending capacity and lending activity, loan demand, deposit levels, investment in digital channels, critical accounting policies and estimates, net interest income, net interest margin, non-interest income, non-interest expense, the Company’s stock repurchase program, consumer behavior and liquidity, the Company’s ability to recruit and retain key employees, the adequacy of the allowance for credit losses, the estimated cost savings associated with the Company’s Better Bank Initiative, income tax deductions, credit quality, the level of credit losses from lending commitments, net interest revenue, interest rates and interest rate sensitivity (including, among other things, the impact of rising or declining interest rates), economic conditions, repricing of loans and time deposits, loan loss experience, liquidity, the Company’s expectations regarding actions by the Federal Home Loan Banks (“FHLB”) and other agencies, capital resources, the expected expenses and cost savings associated with branch closures, market risk, plans for investments in (and cash flows from) securities and investment portfolio strategies, effect of pending and future litigation, staffing initiatives, estimated cost savings associated with the Company’s early retirement program and Better Bank Initiative, legal and regulatory limitations and compliance, and competition.

These forward-looking statements are based on various assumptions and involve inherent risks and uncertainties, and may not be realized due to a variety of factors, including, without limitation: changes in the Company’s operating, acquisition, or expansion strategy; the effects of future economic conditions (including unemployment levels and slowdowns in economic growth), governmental monetary and fiscal policies (including the policies of the Federal Reserve, as well as legislative and regulatory changes); changes in the investment environment and the market for debt securities, including prices therein; changes in tariff policies; general business conditions, as well as conditions within the financial markets, developments impacting the financial services industry, such as bank failures or concerns involving liquidity; changes in real estate values; changes in interest rates and related governmental policies; changes in liquidity, and the availability of and costs associated with obtaining adequate and timely sources of liquidity; increased inflation; changes in the level and composition of deposits, loan demand, deposit flows, and the values of loan collateral, securities and interest sensitive assets and liabilities; changes in credit quality; actions taken by the Company to manage its investment securities portfolio; changes in the securities markets generally or the price of the Company’s common stock specifically; changes in the assumptions used in making the forward-looking statements; developments in information technology affecting the financial industry; cyber threats, attacks or events, including at third parties on which we rely for key services; reliance on third parties for the provision of key services; the ability to collect amounts due under loan agreements; further changes in accounting principles relating to loan loss recognition (current expected credit losses); the costs of evaluating possible acquisitions and the risks inherent in integrating acquisitions; possible adverse rulings, judgments, settlements, fines and other outcomes of pending or future litigation or government actions; market disruptions, including pandemics or significant health hazards, severe weather conditions, natural disasters, terrorist activities, financial crises, political crises, war and other military conflicts (including the ongoing military conflicts between Russia and Ukraine and between Israel and Iran) or other major events, or the prospect of these events; changes in customer behaviors and preferences, including consumer spending, borrowing, and saving habits; the soundness of other financial institutions and indirect

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exposure related to the closings of other financial institutions and their impact on the broader market through other customers, suppliers and partners (or that the conditions which resulted in the liquidity concerns experienced by closed financial institutions may also adversely impact, directly or indirectly, other financial institutions and market participants with which the Company has commercial or deposit relationships); the loss of key employees; fraud that results in material losses or that we have not discovered yet that may result in material losses; increased unemployment; labor shortages; the Company’s ability to manage and successfully integrate its mergers and acquisitions to fully realize cost savings and other benefits associated with those acquisitions; increased delinquency and foreclosure rates on commercial real estate and other loans; significant increases in nonaccrual loan balances; the effects of government legislation; the effects of competition from other commercial banks, thrifts, mortgage banking firms, consumer finance companies, credit unions, securities brokerage firms, insurance companies, money market and other mutual funds, and other financial institutions operating in our market area and elsewhere, including institutions operating regionally, nationally, and internationally, together with such competitors offering banking products and services by mail, cellphone/tablet, telephone, computer, and the internet; the failure of assumptions underlying the establishment of reserves for possible credit losses, fair value for loans, other real estate owned, and those factors set forth under “Risk Factors” and elsewhere in this prospectus supplement and in other filings that have been filed with the SEC. Many of these factors are beyond our ability to predict or control, and actual results could differ materially from those in the forward-looking statements due to these factors and others. In addition, as a result of these and other factors, our past financial performance should not be relied upon as an indication of future performance.

The foregoing factors and the other risks described in “Risk Factors” in our Annual Report, in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2025 and any report subsequently filed with the SEC, and the risks described in this prospectus supplement and the accompanying prospectus should be considered in evaluating any forward-looking statements included or incorporated by reference in this prospectus supplement or the accompanying prospectus. The actual results or developments anticipated by such forward-looking statements may not be realized or, even if substantially realized, they may not have the expected consequences to or effects on our businesses or operations. Readers are cautioned not to put undue reliance on any forward-looking statements. Because of these risks and other uncertainties, our actual future financial condition, results, performance or achievements, or industry results, may be materially different from the results indicated by the forward-looking statements in this prospectus supplement. In addition, our past results of operations are not necessarily indicative of our future results of operations. You should not rely on any forward-looking statements as predictions of future events.

Any forward-looking statement speaks only as of the date on which it is made, and we do not undertake any obligation to update, revise or correct any forward-looking statement, whether as a result of new information, future developments or otherwise, except as required by law. All written or oral forward-looking statements that are made by us or are attributable to us are expressly qualified in their entirety by this cautionary notice, together with those risks and uncertainties described in “Risk Factors” in our Annual Report, in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2025 and in our other filings with the SEC incorporated by reference herein, which are available at the SEC’s website www.sec.gov.

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SUMMARY

The following summary provides a brief overview of certain information appearing elsewhere in this prospectus supplement and the documents incorporated by reference herein, which are described under “Incorporation by Reference.” Because it is a summary, it does not contain all the information that may be important to you. Before making an investment decision to purchase the Notes offered hereby, you should read this entire prospectus supplement and the accompanying prospectus carefully, including the section entitled “Risk Factors” in this prospectus supplement, and the documents incorporated by reference herein and in the accompanying prospectus, including the financial statements and the accompanying notes contained in such documents.

Our Company

Simmons First National Corporation, an Arkansas corporation organized in 1968, is a financial holding company registered under the Bank Holding Company Act of 1956, as amended. The Company is headquartered in Pine Bluff, Arkansas, and had total consolidated assets of $26.69 billion, total consolidated loans of $17.11 billion, total consolidated deposits of $21.82 billion and equity capital of $3.55 billion, each as of June 30, 2025. The Company, through its subsidiaries, provides banking and other financial products and services in markets located in Arkansas, Kansas, Missouri, Oklahoma, Tennessee and Texas.

We seek to build shareholder value by, among other things, focusing on strong asset quality, maintaining strong capital, managing our liquidity position, improving our operational efficiency and opportunistically growing our business, both organically and through mergers with and acquisitions of other financial institutions. Our business philosophy centers on building strong, deep customer relationships through excellent customer service and integrity in our operations. While we have grown in recent years into a regional financial institution and one of the largest bank/financial holding companies headquartered in the State of Arkansas, we continue to emphasize, where practicable, a community-based mindset focused on local associates responding to local banking needs and making business decisions in the markets they serve. Those efforts, though, are buttressed by experienced, centralized support functions in select, critical areas. While we serve a variety of customers and industries, we are not dependent on any single customer or industry.

Our common stock is traded on the Nasdaq Global Select Market under the symbol “SFNC.”

Our principal executive offices are located at 501 Main Street, Pine Bluff, Arkansas 71601, and our telephone number is (870) 541-1000. We also have corporate offices located at 601 E. 3rd Street, Little Rock, Arkansas 72201. We maintain a website at www.simmonsbank.com. We are not incorporating the information on our website into this prospectus supplement, and the information on the website is not included in, nor is it a part of, this prospectus supplement.

Subsidiary Bank

Our wholly-owned subsidiary, Simmons Bank (“Simmons Bank” or the “Bank”), is an Arkansas state-chartered bank that has been in operation since 1903.

Simmons Bank provides banking and other financial products and services to individuals and businesses using a network of approximately 223 financial centers in Arkansas, Kansas, Missouri, Oklahoma, Tennessee and Texas. Simmons Bank offers commercial banking products and services to business and other corporate customers. Simmons Bank extends loans for a broad range of corporate purposes, including (among others) financing commercial real estate, construction of particular properties, commercial and industrial uses, acquisition and equipment financings, and other general corporate needs. Simmons Bank also engages in small business administration (“SBA”) and agricultural finance lending, and it offers corporate credit card products, as well as corporate deposit products and treasury management services.

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In addition, Simmons Bank offers a variety of consumer banking products and services, including (among others) savings, time, and checking deposit products; ATM services; internet and mobile banking platforms; overdraft facilities; real estate, home equity, and other consumer loans and lines of credit; consumer credit card products; and safe deposit boxes. Simmons Bank also maintains a networking arrangement with a third-party broker-dealer that offers brokerage services to Simmons Bank customers, as well as a trust department that provides a variety of trust, investment, agency, and custodial services for individual and corporate clients (including, among others, administration of estates and personal trusts as well as management of investment accounts).

Additionally, Simmons First Insurance Services, Inc. and Simmons First Insurance Services of TN, LLC are wholly-owned subsidiaries of Simmons Bank and are insurance agencies that offer various lines of insurance coverage to individual and commercial customers.

Recent Developments

Common Equity Offering.

On July 23, 2025, the Company closed a public offering (the “Common Equity Offering”) of 18,653,000 shares of its Class A common stock, at a price to the public of $18.50 per share, which includes 2,433,000 shares of the Company’s Class A common stock granted pursuant to the underwriters’ option to purchase additional shares at the public offering price, less underwriting discounts. This offering generated net proceeds of approximately $326.9 million after deducting the underwriting discounts and commissions and estimated offering expenses payable by the Company.

For more information about the Common Equity Offering, see our Current Report on Form 8-K filed with the SEC on July 23, 2025.

Investment Securities Transaction.

On July 23, 2025, we completed steps taken to reposition our balance sheet (the “Investment Securities Transaction”). In the Investment Securities Transaction, the Company and its subsidiaries, as applicable, reclassified its held-to-maturity investment securities to available for sale. The Company and its subsidiaries, as applicable, then sold approximately $3.2 billion (amortized cost basis) of its available for sale investment securities (including certain of those previously classified as held to maturity) for an aggregate price of approximately $2.4 billion. The sale of investment securities resulted in an estimated, realized after-tax loss of approximately $606.7 million (based on an estimated tax rate of 24.3%), which will be recorded during the third quarter of 2025.

For more information about the Investment Securities Transaction, see our Current Report on Form 8-K filed with the SEC on July 25, 2025.

Redemption of Spirit Notes.

During the second quarter of 2025, we issued a notice of redemption to redeem subordinated debt (the “Spirit Notes”) in an aggregate principal amount of $37.0 million that we assumed in April 2022 in connection with our acquisition of Spirit of Texas Bancshares, Inc. The Spirit Notes were redeemed in full on July 31, 2025.

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The Offering

Issuer Simmons First National Corporation.

Securities offered by Us   % Fixed-to-Floating Rate Subordinated Notes due 2035.

Aggregate Principal Amount $   

Issue Price $    

Maturity Date The Notes will mature on     , 2035.

Interest Rate Fixed rate period: A fixed rate per annum of    %, payable semi-annually in arrears on   and   of each year (each, a “fixed rate interest payment date”), commencing on   , 2026. The last fixed rate interest payment date for the fixed rate period will be   , 2030.

Floating rate period: A floating rate per annum equal to the Benchmark (as defined under “Description of the Notes — Interest”) rate (which is expected to be Three-Month Term SOFR (as defined below)) plus a spread of  basis points. For each quarterly interest period during the floating rate period, interest will be payable quarterly in arrears on  ,  ,   and   of each year (each, a “floating rate interest payment date” and, together with the fixed rate interest payment dates, the “interest payment dates”), commencing on     , 2031. Notwithstanding the foregoing, if the Benchmark rate is less than zero, the Benchmark rate shall be deemed to be zero.

For each interest period during the floating rate period, when the Benchmark rate is Three-Month Term SOFR, “Three-Month Term SOFR” means the rate for Term SOFR for a tenor of three months that is published by the Term SOFR Administrator at the Reference Time for any floating rate interest period, as determined by the calculation agent after giving effect to the Three-Month Term SOFR Conventions (each as defined under “Description of the Notes — Interest”).

If the calculation agent determines on or prior to the relevant Reference Time that a Benchmark Transition Event and its related Benchmark Replacement Date (each as defined under “Description of the Notes — Interest”) have occurred with respect to Three-Month Term SOFR, then the provisions under “Description of the Notes — Effect of Benchmark Transition Event,” which are referred to herein as the “benchmark transition provisions,” will thereafter apply to all determinations of the interest rate on the Notes for each interest period occurring after the applicable Benchmark Transition Event and its related Benchmark Replacement Date during the floating rate period. In accordance with the benchmark transition provisions, after a Benchmark Transition Event and its related Benchmark

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Replacement Date have occurred, the interest rate on the Notes for each interest period during the floating rate period will be an annual rate equal to the Benchmark Replacement (as defined under “Description of the Notes”) plus    basis points.

Record Dates Interest on each Note will be payable to the person in whose name such Note is registered on the 15th day immediately preceding the applicable interest payment date.

Day Count Convention Fixed rate period: 360-day year consisting of twelve 30-day months.

Floating rate period: 360-day year and the actual number of days elapsed in each interest period (or any other relevant period).

No Guarantee The Notes will not be guaranteed by any of our subsidiaries. As a result, the Notes will be structurally subordinated to the liabilities of our subsidiaries as discussed below under “Ranking; Subordination.”

Ranking; Subordination The Notes offered by this prospectus supplement will be issued by us under a Subordinated Indenture dated as of March 26, 2018 between Simmons First National Corporation and Wilmington Trust, National Association, as trustee (the “Trustee”), as amended and supplemented by a Second Supplemental Indenture dated as of     , 2025 between Simmons and the Trustee. We refer to the Subordinated Indenture, as amended and supplemented by the Second Supplemental Indenture, as the “Indenture.” The Notes will be Simmons’ unsecured, subordinated obligations and:

• will rank junior in right of payment and upon our liquidation to any of our existing and all future Senior Indebtedness (as defined in the Indenture), all as described under “Description of the Notes”;

• will rank junior in right of payment and upon our liquidation to any of our future general creditors;

• will rank equal in right of payment and upon our liquidation with all of our future indebtedness the terms of which provide that such indebtedness ranks equally with promissory notes, bonds, debentures and other evidences of indebtedness of types that include the Notes, including our 5.00% Fixed-to-Floating Rate Subordinated Notes due 2028 (the “2028 Notes”);

• will rank senior in right of payment and upon our liquidation to any of our future indebtedness the terms of which provide that such indebtedness ranks junior in right of payment to promissory notes, bonds, debentures and other evidences of indebtedness of types that include the Notes; and

• will be structurally subordinated to our existing and future indebtedness, deposits and other liabilities of the Company’s

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current and future subsidiaries, including without limitation, Simmons Bank’s liabilities to depositors in connection with the deposits, as well as liabilities to general creditors and liabilities arising in the ordinary course of business or otherwise.

As of June 30, 2025, on a consolidated basis, our total liabilities totaled approximately $23.1 billion, which includes approximately $21.8 billion of deposit liabilities. As of June 30, 2025, we also had approximately $366.4 million of outstanding principal and accrued but unpaid interest related to subordinated debentures that rank equally with the Notes, of which $37.0 million related to the Spirit Notes was redeemed in full on July 31, 2025.

The Indenture governing the Notes does not limit the amount of additional indebtedness we or our subsidiaries may incur.

Form and Denomination The Notes will be offered in book-entry form only through the facilities of DTC in minimum denominations of $1,000 and integral multiples of $1,000 in excess thereof.

Optional Redemption We may, at our option, beginning with the interest payment date of    , 2030, and on any interest payment date thereafter, redeem the Notes, in whole or in part, from time to time, subject to obtaining the prior approval of the Federal Reserve to the extent such approval is then required under the rules of the Federal Reserve, at a redemption price equal to 100% of the principal amount of the Notes being redeemed plus accrued and unpaid interest to, but excluding, the date of redemption.

Special Redemption We may also redeem the Notes at any time prior to their maturity, including prior to    , 2030, in whole, but not in part, subject to obtaining the prior approval of the Federal Reserve to the extent such approval is then required under the rules of the Federal Reserve, if: (i) we receive an opinion of independent tax counsel to the effect that as a result of an amendment or change (including any announced prospective amendment or change) in law occurs, or an administrative or judicial action is announced or taken or there is an amendment to or change in any official position with respect to, or interpretation of, an administrative or judicial action or a law or regulation that differs from the previously generally accepted position or interpretation, in each case that, as a result of which, there is more than an insubstantial risk that interest payable by us on the Notes is not, or within 90 days of the date of such opinion, will not be deductible by us, in whole or in part, for U.S. federal income tax purposes; (ii) a subsequent event occurs that, as a result of which, there is more than an insubstantial risk that we would not be entitled to treat the Notes as Tier 2 capital for regulatory capital purposes; or (iii) we are required to register as an investment company under the Investment Company Act of 1940, as amended; in each case, at a redemption price equal to 100% of the

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principal amount of the Notes plus any accrued and unpaid interest to, but excluding, the redemption date. For more information, see “Description of the Notes — Redemption.”

Sinking Fund There is no sinking fund for the Notes.

Further Issuances The Notes will initially be limited to an aggregate principal amount of $    . We may, from time to time, without notice to or consent of the holders of the Notes, increase the aggregate principal amount of the Notes outstanding by issuing additional Notes in the future with the same terms as the Notes, except for the issue date, the offering price and the first interest payment date, and such additional notes may be consolidated with the Notes issued in this offering and form a single series; provided that if any such additional notes are not fungible with the Notes for U.S. federal income tax purposes, such additional notes will have a separate CUSIP or other identifying number.

Use of Proceeds We estimate that the net proceeds from this offering will be approximately $    million, after deducting the underwriting discount and our estimated offering expenses.

We intend to use the net proceeds of this offering, together with cash on hand, if needed, to repay in full our outstanding $330 million principal amount of the 2028 Notes on October 1, 2025 and for general corporate purposes. See “Use of Proceeds.”

Listing The Notes will not be listed on any securities exchange or quoted on any quotation system. Currently, there is no market for the Notes, and there can be no assurances that any public market for the Notes will develop.

ERISA Considerations For a discussion of certain prohibited transactions and fiduciary duty issues pertaining to purchases by or on behalf of an employee benefit plan, see “Certain ERISA Considerations.”

U.S. Federal Income Tax Considerations For a discussion of material U.S. federal income tax considerations of purchasing, owning and disposing of the Notes, see “Material U.S. Federal Income Tax Considerations.”

Governing Law The Notes and the Indenture will be governed by the laws of the State of New York.

Trustee Wilmington Trust, National Association.

Risk Factors An investment in the Notes involves risks. You should carefully read and consider the information set forth under the heading “Risk Factors” beginning on page S-11 of this prospectus supplement, on page 4 of the accompanying prospectus, under the heading “Part I. Item 1A. Risk Factors” in our Annual Report, and in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2025, as updated by our subsequent filings with the SEC, which are incorporated herein by reference, before deciding to invest in the Notes.

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RISK FACTORS

An investment in our securities involves a significant degree of risk. The material risks and uncertainties that management believes affect us are described below. Before you decide to invest in our securities, you should carefully read and consider all of the information contained in this prospectus supplement, including the risks and uncertainties described below and under “Cautionary Note Regarding Forward-Looking Statements” in this prospectus supplement, and the other documents incorporated by reference into this prospectus supplement, including, among others, the risks and uncertainties described under the heading “Risk Factors” beginning on page 4 of the accompanying prospectus, under the heading “Part I. Item 1A. Risk Factors” in our Annual Report, and in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2025, as updated by our subsequent filings with the SEC. Any of these risks, if they are realized, could have an adverse effect on our business, financial condition and results of operations, and consequently, the value of the Notes. In any such case, you could lose all or a portion of your original investment. Further, additional risks and uncertainties not currently known to us or that we currently believe to be immaterial may also adversely affect us. This prospectus supplement also contains forward-looking statements that involve risks and uncertainties. See the section entitled “Cautionary Note Regarding Forward-Looking Statements.”

The Notes will be unsecured and subordinated to our existing and future Senior Indebtedness.

The Notes will be our unsecured, subordinated obligations. Accordingly, they will be junior in right of payment to any existing and all future senior indebtedness, and in certain events of insolvency, to other financial obligations as described under “Description of the Notes.” Our senior indebtedness includes all indebtedness, except indebtedness that is expressly subordinated to or ranked pari passu with the Notes, subject to certain exceptions. The Notes will rank equally with all other unsecured subordinated indebtedness of the Company issued in the future under the Indenture. In addition, the Notes will be structurally subordinated to all existing and future indebtedness, liabilities and other obligations, including deposits, of our subsidiaries, including Simmons Bank. As of June 30, 2025, the Company’s outstanding indebtedness and other liabilities totaled approximately $23.1 billion, which includes approximately $21.8 billion of deposits and $617.8 million of FHLB advances that rank structurally senior to the Notes, $16.5 million of other long-term debt that ranks senior to the Notes, and $366.4 million of outstanding subordinated debt securities that rank equal in right of payment to the Notes. On July 31, 2025, we redeemed $37.0 million of our outstanding Spirit Notes. We intend to use the net proceeds from this offering, together with cash on hand, if needed, to repay our outstanding $330 million of the 2028 Notes and for general corporate purposes; however, we may determine not to redeem the 2028 Notes or to redeem only a portion of the 2028 Notes.

Since the Notes will not be secured by any of our assets, the Notes will be effectively subordinated to all of our secured indebtedness to the extent of the value of the assets securing such indebtedness. The Indenture governing the Notes does not limit the amount of senior indebtedness and other financial obligations or secured obligations that we or our subsidiaries may incur. Accordingly, we may incur substantial additional indebtedness, including additional indebtedness ranking senior to or on a parity basis with the Notes in the future.

As a result of the subordination provisions described above, holders of the Notes may not be fully repaid in the event of our bankruptcy, liquidation or reorganization.

The Notes will not be insured or guaranteed by the FDIC, any other governmental agency or any of our subsidiaries. The Notes will be structurally subordinated to the indebtedness and other liabilities of our subsidiaries, which means that creditors of our subsidiaries generally will be paid from those subsidiaries’ assets before holders of the Notes would have any claims to those assets.

The Notes are not bank deposits and are not insured or guaranteed by the FDIC or any other governmental agency. The Notes will be obligations of Simmons First National Corporation only and will not be obligations of, or guaranteed by, any of our subsidiaries, including Simmons Bank. The Notes will be structurally subordinated to all existing and future indebtedness and other liabilities of our subsidiaries, which means that creditors of our

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subsidiaries (including, in the case of Simmons Bank, its depositors) generally will be paid from those subsidiaries’ assets before holders of the Notes would have any claims to those assets. Even if we become a creditor of any of our subsidiaries, our rights as a creditor would be subordinate to any security interest in the assets of that subsidiary and any debt of that subsidiary senior to that held by us, and our rights could otherwise be subordinated to the rights of other creditors and depositors of that subsidiary. Furthermore, none of our subsidiaries is under any obligation to make payments to us, and any payments to us would depend on the earnings or financial condition of our subsidiaries and various business considerations. Statutory, contractual or other restrictions also limit our subsidiaries’ ability to pay dividends or make distributions, loans or advances to us. For these reasons, we may not have access to any assets or cash flows of our subsidiaries to make interest and principal payments on the Notes.

The Indenture governing the Notes does not contain any limitations on our ability to incur additional indebtedness, grant or incur a lien on our assets, sell or otherwise dispose of assets, pay dividends or repurchase our capital stock.

Neither we nor any of our subsidiaries is restricted from incurring additional indebtedness or other liabilities, including additional senior or subordinated indebtedness, under the Indenture governing the terms of the Notes. If we incur additional indebtedness or liabilities, our ability to pay our obligations on the Notes could be adversely affected. We expect that we will from time to time incur additional indebtedness and other liabilities. In addition, we are not restricted under the Indenture governing the Notes from granting or incurring a lien on any of our assets, selling or otherwise disposing of any of our assets, paying dividends or issuing or repurchasing our securities.

In addition, there are no financial covenants in the Indenture governing the Notes. You are not protected under the Indenture governing the Notes in the event of a highly leveraged transaction, reorganization, default under our existing indebtedness, restructuring, merger or similar transaction that may adversely affect you.

Payments on the Notes will depend on receipt of dividends and distributions from our subsidiaries.

We are a financial holding company, and we conduct substantially all of our operations through subsidiaries, including Simmons Bank. We depend on dividends, distributions and other payments from our subsidiaries to meet our obligations, including to fund payments on the Notes, and to provide funds for payment of dividends to our shareholders, to the extent declared by our board of directors. There are various legal limitations on the extent to which Simmons Bank and our other subsidiaries can finance or otherwise supply funds to us (by dividend or otherwise) and certain of our affiliates. For example, Simmons Bank may not pay us dividends if, after paying those dividends, it would fail to meet the required minimum levels under risk-based capital guidelines and the minimum leverage and tangible capital ratio requirements. Under the Federal Deposit Insurance Act, an insured depository institution such as Simmons Bank is prohibited from making capital distributions, including the payment of dividends, if, after making such distribution, the institution would become “undercapitalized.” Simmons Bank may declare and pay dividends out of its net profits, unless there is an impairment of capital. Further, contractual or other restrictions may also limit our subsidiaries’ abilities to pay dividends or make distributions, loans or advances to us. See “Item 1 - Business - Supervision and Regulation” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024. For these reasons, we may not have access to any assets or cash flow of our subsidiaries to make principal or interest payments on the Notes.

We may not be able to generate sufficient cash to service all of our debt, including the Notes.

Our ability to make scheduled payments of principal and interest, or to satisfy our obligations in respect of our debt or to refinance our debt, will depend on our future performance of our operating subsidiaries. Prevailing economic conditions (including interest rates), regulatory constraints, including, among other things, limiting distributions to us from Simmons Bank and required capital levels with respect to Simmons Bank and certain of our nonbank subsidiaries, and financial, business and other factors, many of which are beyond our control, will

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also affect our ability to meet these needs. Our subsidiaries may not be able to generate sufficient cash flows from operations, or we may be unable to obtain future borrowings in an amount sufficient to enable us to pay our debt, or to fund our other liquidity needs. We may need to refinance all or a portion of our debt on or before maturity. We may not be able to refinance any of our debt when needed on commercially reasonable terms or at all.

Regulatory guidelines may restrict our ability to pay the principal of, and accrued and unpaid interest on, the Notes, regardless of whether we are the subject of an insolvency proceeding.

As a financial holding company, our ability to pay the principal of, and interest on, the Notes is subject to the rules and guidelines of the Federal Reserve regarding capital adequacy. We intend to treat the Notes as “Tier 2 capital” under these rules and guidelines. The Federal Reserve guidelines generally require us to review the effects of the cash payment of Tier 2 capital instruments, such as the Notes, on our overall financial condition. The guidelines also require that we review our net income for the current and past four quarters, and the amounts we have paid on Tier 2 capital instruments for those periods, as well as our projected rate of earnings retention. Moreover, pursuant to federal law and Federal Reserve regulations, as a bank holding company, we are required to act as a source of financial and managerial strength to Simmons Bank and commit resources to its support, including, without limitation, the guarantee of its capital plans if it is undercapitalized. Such support may be required at times when we may not otherwise be inclined or able to provide it. As a result of the foregoing, we may be unable to pay accrued interest on the Notes on one or more of the scheduled interest payment dates, or at any other time, or the principal of the Notes at the maturity of the Notes.

If we were to be the subject of a bankruptcy proceeding under Chapter 11 of the U.S. Bankruptcy Code, then the bankruptcy trustee would be deemed to have assumed, and would be required to cure, immediately any deficit under any commitment we have to any of the federal banking agencies to maintain the capital of Simmons Bank, and any other insured depository institution for which we have such a responsibility, and any claim for breach of such obligation would generally have priority over most other unsecured claims.

Holders of the Notes will have limited rights, including limited rights of acceleration, if there is an event of default.

Payment of principal on the Notes may be accelerated only in the case of certain events of bankruptcy or insolvency involving us or Simmons Bank. There is no automatic acceleration, or right of acceleration, in the case of default in the payment of principal of or interest on the Notes, or in the performance of any of our other obligations under the Notes or the Indenture governing the Notes. Our regulators can, in the event we become subject to an enforcement action, require Simmons Bank to not pay dividends to us, and to prevent our payment of interest or principal on the Notes and any dividends on our capital stock, but such limits will not permit acceleration of the Notes. See “Description of the Notes — Events of Default; Acceleration of Payment; Limitation on Suits” in this prospectus supplement.

An active trading market for the Notes may not develop.

The Notes constitute a new issue of securities for which there is no existing trading market. We do not intend to apply for listing of the Notes on any securities exchange or for quotation of the Notes in any automated dealer quotation system. We cannot provide you with any assurance regarding whether a trading market for the Notes will develop, the ability of holders of the Notes to sell their Notes or the prices at which holders may be able to sell their Notes. The underwriters have advised us that they currently intend to make a market in the Notes. The underwriters, however, are not obligated to do so, and any market-making with respect to the Notes may be discontinued at any time without notice. You should also be aware that there may be a limited number of buyers when you decide to sell your Notes. This may affect the price you receive for your Notes or your ability to sell your Notes at all.

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If a trading market for the Notes develops, changes in the debt markets, among others, could adversely affect your ability to liquidate your investment in the Notes and the market price of the Notes.

Many factors could affect the trading market for, and the trading value of, the Notes. These factors include: the method of calculating the principal, premium, if any, interest or other amounts payable, if any, on the Notes; the time remaining to the maturity of the Notes; the ranking of the Notes; the redemption features of the Notes; the outstanding amount of subordinated notes with terms identical to the Notes offered hereby; the prevailing interest rates being paid by other companies similar to us; changes in U.S. interest rates; whether the ratings on the Notes or us provided by any rating agency have changed; our financial condition, financial performance and future prospects; the level, direction and volatility of market interest rates generally; general economic conditions of the capital markets in the United States; and geopolitical conditions and other financial, political, regulatory, and judicial events that affect the capital markets generally. The condition of the financial markets and prevailing interest rates have fluctuated significantly in the past and are likely to fluctuate in the future. Such fluctuations could adversely affect the trading market (if any) for, and the market price of, the Notes.

Because the Notes may be redeemed at our option under certain circumstances prior to their maturity, if we elect to redeem all or any portion of the Notes, you may be subject to reinvestment risk.

On or after    , 2030, we may, at our option, redeem the Notes in whole or in part on each interest payment date. In addition, we may also redeem the Notes prior to maturity, at our option, in whole but not in part, if: (i) we receive an opinion from independent tax counsel to the effect that as a result of an amendment or change (including any announced prospective amendment or change) in law, an administrative or judicial action (including an announcement thereof) or an amendment to or change in any official position with respect to, or interpretation of, an administrative or judicial action or a law or regulation that differs from the previously generally accepted position or interpretation, there is more than an insubstantial risk that interest payable by us on the Notes is not, or within 90 days of the date of such opinion, will not be deductible by us, in whole or in part, for U.S. federal income tax purposes; (ii) a subsequent event occurs that, as a result of which, there is more than an insubstantial risk that we would not be entitled to treat the Notes as Tier 2 capital for regulatory capital purposes; or (iii) we are required to register as an investment company under the Investment Company Act of 1940, as amended. The redemption price for any redemption is 100% of the principal amount of the Notes, plus accrued and unpaid interest thereon to, but excluding, the date of redemption. Any early redemption of the Notes will be subject to the receipt of the approval of the Federal Reserve, to the extent then required under applicable laws or regulations, including capital regulations. Any such redemption may have the effect of reducing the income or return that you may receive on an investment in the Notes by reducing the term of the investment. Under current regulatory capital guidelines, the aggregate principal amount of the Notes that will count as Tier 2 capital will be reduced by 20% in each of the last five years prior to the Maturity Date of the Notes. As a result, we may be more likely to redeem the Notes prior to their Maturity Date. If this occurs, you may not be able to reinvest the proceeds at an interest rate comparable to the rate paid on the Notes. See “Description of the Notes — Redemption.”

We may elect to redeem the Notes on or after the date on which they become redeemable at our option; however, investors should not expect us to make such election on such date when the Notes are first redeemable. Under Federal Reserve regulations, unless the Federal Reserve authorizes us in writing to do otherwise, we may not redeem the Notes unless they are replaced with other Tier 2 capital instruments or unless we can demonstrate to the satisfaction of the Federal Reserve that, following redemption, we will continue to hold capital commensurate with our risk.

Our credit ratings may not reflect all risks of an investment in the Notes, and changes in our credit ratings may adversely affect your investment in the Notes.

The credit ratings of our indebtedness are an assessment by rating agencies of our ability to pay our debts when due. These ratings are not recommendations to purchase, hold or sell the Notes, inasmuch as the ratings do

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not comment as to market price or suitability for a particular investor, are limited in scope, and do not address all material risks relating to an investment in the Notes, but rather reflect only the view of each rating agency at the time the rating is issued. The credit ratings assigned to the Notes may not reflect the potential impact of all risks related to structure and other factors on any trading market for, or trading value of, the Notes. In addition, real or anticipated changes in our credit ratings will generally affect the trading market for, or the trading value of, the Notes. Accordingly, you should consult your own financial and legal advisors as to the risks entailed by an investment in the Notes and the suitability of investing in the Notes in light of your particular circumstances.

Our board of directors and management will have broad discretion in allocating the net proceeds of the offering. Our failure to effectively utilize such net proceeds may have an adverse effect on our financial performance.

We intend to use the net proceeds from this offering as set forth under “Use of Proceeds.” However, we are not required to apply any portion of the net proceeds of this offering for any particular purpose, and our management could use the proceeds for purposes other than those contemplated at the time of this offering. Accordingly, our board of directors and management will have broad discretion in the application of the net proceeds from this offering, and you will be relying on the judgment of our management regarding the application of these proceeds. You will not have the opportunity, as part of your investment decision, to assess whether we are using the proceeds appropriately. Our management might not apply our net proceeds in ways that ultimately increase the value of your investment. If we do not invest or apply the net proceeds from this offering in ways that enhance shareholder value, we may fail to achieve expected financial results, which could have an adverse effect on our financial performance. See “Use of Proceeds.”

The amount of interest payable on the Notes will vary after    , 2030.

During the fixed rate period, the Notes will bear interest at an initial rate of    % per annum. Thereafter, the Notes will bear interest at a floating rate per annum equal to the Benchmark rate (which is expected to be Three-Month Term SOFR) plus   basis points, subject to the provisions under “Description of the Notes — Interest.” The per annum interest rate that is determined at the Reference Time for each interest period will apply to the entire quarterly interest period following such determination date even if the Benchmark rate increases during that period.

Floating rate notes bear additional significant risks not associated with fixed rate debt securities. These risks include fluctuation of the interest rates and the possibility that you will receive an amount of interest that is lower than expected. We have no control over a number of matters, including, without limitation, economic, financial, and political events, that are important in determining the existence, magnitude, and longevity of market volatility and other risks and their impact on the value of, or payments made on, the Notes. In recent years, interest rates have been volatile, and that volatility may be expected in the future.

You should not rely on indicative or historical data concerning SOFR.

The interest rate during the floating rate period will be determined using Three-Month Term SOFR (unless a Benchmark Transition Event and its related Benchmark Replacement Date occur with respect to Three-Month Term SOFR, in which case the rate of interest will be based on the next-available Benchmark Replacement). In the following discussion of the secured overnight financing rate (as further described under “Description of the Notes — Interest.”), when we refer to SOFR-linked subordinated notes, we mean the Notes at any time when the interest rate on the Notes is or will be determined based on SOFR, including Three-Month Term SOFR.

SOFR is published by the Federal Reserve Bank of New York (“FRBNY”) and is intended to be a broad measure of the cost of borrowing cash overnight collateralized by U.S. Treasury securities. FRBNY reports that SOFR includes all trades in the Broad General Collateral Rate, plus bilateral U.S. Treasury repurchase agreement (“repo”) transactions cleared through the delivery-versus-payment service offered by the Fixed Income Clearing

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Corporation (the “FICC”), a subsidiary of The Depository Trust & Clearing Corporation (“DTCC”). SOFR is filtered by FRBNY to remove a portion of the foregoing transactions considered to be “specials.” According to FRBNY, “specials” are repos for specific-issue collateral which take place at cash-lending rates below those for general collateral repos because cash providers are willing to accept a lesser return on their cash in order to obtain a particular security.

FRBNY reports that SOFR is calculated as a volume-weighted median of transaction-level tri-party repo data collected from The Bank of New York Mellon, which currently acts as the clearing bank for the tri-party repo market, as well as general collateral finance repo transaction data and data on bilateral U.S. Treasury repo transactions cleared through the FICC’s delivery-versus-payment service.

FRBNY states that it obtains information from DTCC Solutions LLC, an affiliate of DTCC. FRBNY currently publishes SOFR daily on its website. FRBNY states on its publication page for SOFR that use of SOFR is subject to important disclaimers, limitations and indemnification obligations, including that FRBNY may alter the methods of calculation, publication schedule, rate revision practices or availability of SOFR at any time without notice.

On July 29, 2021, the Alternative Reference Rates Committee (the “ARRC”) convened by the Federal Reserve and FRBNY formally recommended the use of the CME Group’s computation of forward-looking SOFR term rates, which are calculated by the CME Group based on SOFR futures. It is currently anticipated that Three-Month Term SOFR, for purposes of the Notes, will be based on the CME Group’s forward-looking SOFR term rates with a tenor of three months. FRBNY started publishing SOFR in April 2018. FRBNY has also started publishing historical indicative SOFRs dating back to 2014, although such historical indicative data inherently involves assumptions, estimates and approximations. Investors should not rely on such historical indicative data or on any historical changes or trends in SOFR as an indicator of the future performance of SOFR.

SOFR may be more volatile than other benchmark or market rates.

Since the initial publication of SOFR, daily changes in the rate have, on occasion, been more volatile than daily changes in comparable benchmark or market rates, and SOFR over time may bear little or no relation to the historical actual or historical indicative data. In addition, the return on and value of the Notes may fluctuate more than floating rate securities that are linked to other rates.

Changes in SOFR could adversely affect holders of the Notes.

Because SOFR is published by FRBNY based on data received from other sources, we have no control over its determination, calculation or publication. There is no assurance that SOFR will not be discontinued or fundamentally altered in a manner that is materially adverse to the interests of investors in the Notes. If the manner in which SOFR is calculated is changed, that change may result in a reduction in the amount of interest that accrues on the Notes during the floating rate period, which may adversely affect the trading prices of the Notes. In addition, the interest rate on the SOFR-linked subordinated notes for any day will not be adjusted for any modification or amendment to SOFR for that day that FRBNY may publish if the interest rate for that day has already been determined prior to such publication. Further, if the Benchmark rate on the Notes during the floating rate period for any interest period declines to zero or becomes negative, interest will only accrue on the Notes at a rate equal to the spread of    % per annum with respect to that interest period. Changes in SOFR could have a material adverse effect on the yield on, value of and market for the Notes.

A decrease in SOFR would reduce the rate of interest on the Notes.

The interest rate to be borne by the Notes is based on a spread over SOFR or, if the calculation agent determines prior to the relevant reference time that a Benchmark Transition Event and its related Benchmark Replacement Date have occurred with respect to Three-Month Term SOFR, upon the applicable Benchmark

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Replacement. Changes in SOFR or such Benchmark Replacement will affect the rate at which the Notes accrue interest and the amount of interest payments on the Notes. Any decrease in SOFR or such Benchmark Replacement will lead to a decrease in the Notes’ interest rate.

Any Benchmark Replacement may not be the economic equivalent of Three-Month Term SOFR.

Under the benchmark transition provisions of the Notes, if the calculation agent determines that a Benchmark Transition Event and its related Benchmark Replacement Date have occurred with respect to Three-Month Term SOFR, then the interest rate on the Notes during the floating rate period will be determined using the next-available Benchmark Replacement (which may include a related Benchmark Replacement Adjustment (as defined under “Description of the Notes — Interest”)). However, the Benchmark Replacement may not be the economic equivalent of Three-Month Term SOFR. For example, Compounded SOFR (as defined under “Description of the Notes — Effect of Benchmark Transition Event”), the first available Benchmark Replacement, is the compounded average of SOFRs for the applicable Corresponding Tenor (as defined under “Description of the Notes — Interest”), with the rate, or methodology for this rate, and conventions for this rate being established by the calculation agent as described in the section titled “Description of the Notes,” while Three-Month Term SOFR is intended to be a forward-looking rate with a tenor of three months. In addition, very limited market precedent exists for securities that use Compounded SOFR as the rate basis, and the method for calculating Compounded SOFR in those precedents varies. Further, the ISDA Fallback Rate (as defined under “Description of the Notes”), which is another Benchmark Replacement, has not yet been established and may change over time.

The implementation of Benchmark Replacement Conforming Changes could adversely affect the amount of interest that accrues on the Notes and the trading prices for the Notes.

Under the benchmark transition provisions of the Notes, if a particular Benchmark Replacement or Benchmark Replacement Adjustment cannot be determined, then the next-available Benchmark Replacement or Benchmark Replacement Adjustment will apply. These replacement rates and adjustments may be selected or formulated by (i) the Federal Reserve and/or the FRBNY, or a committee officially endorsed or convened by the Federal Reserve and/or the FRBNY or any successor thereto (“Relevant Governmental Body”) (such as the ARRC), (ii) International Swaps and Derivatives Association, Inc., or any successor thereto, or (iii) in certain circumstances, the calculation agent. In addition, the benchmark transition provisions expressly authorize the calculation agent to make certain changes, which are defined in the terms of the Notes as “Benchmark Replacement Conforming Changes,” with respect to, among other things, the determination of interest periods, and the timing and frequency of determining rates and making payments of interest. The application of a Benchmark Replacement and Benchmark Replacement Adjustment, and any implementation of Benchmark Replacement Conforming Changes, could result in adverse consequences to the amount of interest that accrues on the Notes during the floating rate period, which could adversely affect the return on, value of and market for the Notes. Further, there is no assurance that the characteristics of any Benchmark Replacement will be similar to the then-current Benchmark that it is replacing, or that any Benchmark Replacement will produce the economic equivalent of the then-current Benchmark that it is replacing.

Any failure of SOFR to maintain market acceptance could adversely affect the Notes.

SOFR was developed for use in certain U.S. dollar derivatives and other financial contracts as a replacement for the London Interbank Offered Rate, or LIBOR, in part because it is considered a representation of general funding conditions in the overnight U.S. Treasury repurchase agreement market. However, as a rate based on transactions secured by U.S. Treasury securities, SOFR does not measure bank-specific credit risk and, as a result, is less likely to correlate with the unsecured short-term funding costs of banks. This may mean that market participants would not consider SOFR a suitable replacement or successor for all of the purposes for which LIBOR historically has been used (including, without limitation, as a representation of the unsecured short-term funding costs of banks), which may, in turn, lessen market acceptance of SOFR. Any failure of SOFR to

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maintain wide market acceptance could adversely affect the return on and value of the Notes and the price at which investors can sell the Notes in the secondary market.

A change in the Benchmark rate may be treated as a significant modification of the Notes for tax purposes, which could result in taxable gain or loss to holders.

If a term of the Notes, such as the interest rate, is altered and the degree to which the Notes are altered is economically significant, the Notes will be treated as exchanged for the modified notes for federal tax purposes. A deemed exchange of the Notes could result in gain or loss to the holders. Thus, if the Benchmark rate is replaced with a rate other than the Three-Month Term SOFR, such replacement could adversely affect the holders of the Notes.

The secondary trading market for Notes linked to Three-Month Term SOFR may be limited.

The Notes will have no established trading market when issued, and an established trading market may never develop or may not be very liquid. Market terms for debt securities linked to Three-Month Term SOFR (such as the Notes) such as the applicable spread may evolve over time and, as a result, trading prices of the Notes may be lower than those of later-issued debt securities that are linked to Three-Month Term SOFR. Similarly, if Three-Month Term SOFR does not prove to be widely used in debt securities similar to the Notes, the trading price of the Notes may be lower than that of debt securities linked to rates that are more widely used. Investors in the Notes may not be able to sell such Notes at all or may not be able to sell such Notes at prices that will provide a yield comparable to similar investments that have a developed secondary market. Further, investors wishing to sell the Notes in the secondary market during the floating rate period will have to make assumptions as to the future performance of Three-Month Term SOFR during the applicable floating rate period in which they intend the sale to take place. As a result, investors may suffer from increased pricing volatility and market risk.

The price at which the Notes may be sold prior to maturity will depend on a number of factors and may be substantially less than the amount for which they were originally purchased.

Some of these factors include, but are not limited to: (i) actual or anticipated changes in the level of Three-Month Term SOFR, (ii) volatility of the level of Three-Month Term SOFR, (iii) changes in interest and yield rates, (iv) any actual or anticipated changes in our credit ratings or credit spreads and (v) the time remaining to maturity of such Notes. Generally, the longer the time remaining to maturity and the more tailored the exposure, the more the market price of the Notes will be affected by the other factors described in the preceding sentence. This can lead to significant adverse changes in the market price of securities like the Notes. Depending on the actual or anticipated level of Three-Month Term SOFR, the market value of the Notes may decrease and you may receive substantially less than 100% of the issue price if you are able to sell your Notes prior to maturity.

The calculation agent will make determinations with respect to the Notes.

During each Floating Rate Interest Payment Period, the calculation agent will determine the interest rates with respect to the Notes using Three-Month Term SOFR as further described in this prospectus supplement. In addition, if a Benchmark Transition Event and its related Benchmark Replacement Date have occurred, the calculation agent will make certain determinations with respect to the Notes in the calculation agent’s sole discretion as further described under “Description of the Notes — Determinations and Decisions.” Any of these determinations may adversely affect the payout to investors. Moreover, certain determinations made by us or our designee may require the exercise of discretion and the making of subjective judgments, such as with respect to the Benchmark rate or the occurrence or non-occurrence of a Benchmark Transition Event and any Benchmark Replacement Conforming Changes. These potentially subjective determinations may adversely affect the payout to you on the Notes. For further information regarding these types of determinations, see “Description of the Notes — Determinations and Decisions” and related definitions below.

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USE OF PROCEEDS

We estimate that the net proceeds to us from this offering will be approximately $    , after deducting underwriting discounts and commissions and the estimated offering expenses payable by us.

We intend to use the net proceeds, together with cash on hand, if needed, from this offering to repay our outstanding $330 million of the 2028 Notes and for general corporate purposes. We anticipate delivering a redemption notice following this offering, with such redemption expected to be effective on October 1, 2025. The redemption of the 2028 Notes is not contingent on this offering or the amount of proceeds resulting from this offering.

The 2028 Notes currently bear interest at a floating rate per annum equal to the three-month term SOFR, plus a spread of 241.161 basis points, payable quarterly in arrears on January 1, April 1, July 1 and October 1 of each year. The 2028 Notes are scheduled to mature on April 1, 2028. We may elect to redeem early the 2028 Notes, in whole or in part, on any future interest payment date (January 1, April 1, July 1 and October 1 of each year) at a redemption price equal to 100% of the principal amount plus any accrued and unpaid interest, subject to regulatory approval to the extent such regulatory approval is then required. We may determine not to redeem the 2028 Notes or to redeem only a portion of the 2028 Notes. This prospectus supplement is not an offer to purchase or a solicitation of an offer to sell the 2028 Notes. In addition, the redemption will be made solely pursuant to a redemption notice delivered pursuant to the indenture governing such existing 2028 Notes, and nothing contained in this prospectus supplement constitutes a notice of redemption of the 2028 Notes.

Our board of directors and management will have broad discretion in the application of the net proceeds from this offering, and investors will be relying on the judgment of our board of directors and management with regard to the use of these net proceeds. Please see “Risk Factors — Our board of directors and management will have broad discretion in allocating the net proceeds of the offering. Our failure to effectively utilize such net proceeds may have an adverse effect on our financial performance.” Pending the use of the net proceeds from this offering as described above, we may invest the net proceeds in cash or short-term marketable securities.

The foregoing represents our intentions based upon our present plans and business conditions. The occurrence of unforeseen events or changed business conditions, however, could result in the application of the net proceeds of the offering in a manner other than as described in this prospectus supplement.

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UNAUDITED PRO FORMA FINANCIAL INFORMATION

The following pro forma balance sheet gives effect, based on financial information as of June 30, 2025, to the completion of the Common Equity Offering, the Investment Securities Transaction and the redemption of the Spirit Notes. The following pro forma balance sheet also gives effect to the completion of this offering and the full repayment of our 5.00% Fixed-to-Floating Rate Subordinated Notes due 2028 (the “2028 Notes”).

Such unaudited pro forma financial information is based on various adjustments, assumptions and preliminary estimates as described in the accompanying notes, and does not purport to be an indication of our financial condition or results of operations after giving effect to the Common Equity Offering, the Investment Securities Transaction or the redemption of the Spirit Notes, or following the completion of the offering or the repayment of the 2028 Notes. Such unaudited pro forma financial information has been prepared assuming a tax rate of 24.3%. Our actual financial condition and results of operations may not be consistent with, or evident from, the pro forma financial information. In addition, the assumptions used in preparing the pro forma financial information may not prove to be accurate, and other factors may affect our actual financial condition or results of operations. Our potential for future business performance and financial results must be considered in light of the risks, uncertainties, expenses and difficulties described in this prospectus supplement, the accompanying prospectus, and the documents incorporated herein by reference.

This pro forma financial information should be read in conjunction with, and is qualified in its entirety by reference to, the information appearing under “Use of Proceeds” and “Risk Factors” included elsewhere in this prospectus supplement, as well as our historical financial statements and related notes that are incorporated by reference into this prospectus supplement. See the table below for the unaudited pro forma balance sheet and accompanying notes. The table also includes our key regulatory capital ratios, which reflect the impact of the transactions described above.

($ in thousands, except per share data)		June 30, 2025				Common Equity Offering				HTM Transfer to AFS (1)				Balance Sheet Repositioning (3)				Pro Forma June 30, 2025				Notes Offering (10)				Redemption of 2028 Notes (11)				Pro Forma Adjusted
Assets
Cash and cash equivalents		$	644,462			$	326,993			$	—			$	(363,993	)		$	607,462			$	296,500			$	(330,000	)		$	573,962
AFS Securities			2,405,320				—				2,929,625				(1,869,344	)			3,465,601				—				—				3,465,601
HTM Securities			3,591,531				—				(3,591,531	)			—				—				—				—				—
Loans:
Total loans			17,128,068				—				—				—				17,128,068				—				—				17,128,068
Allowance for credit losses on loans			(253,537	)			—				—				—				(253,537	)			—				—				(253,537	)
Net loans			16,874,531				—				—				—				16,874,531				—				—				16,874,531
Intangible assets			1,411,416				—				—				—				1,411,416				—				—				1,411,416
Other assets			1,766,360				—				160,843				(194,762	)			1,732,441				—				—				1,732,441
Total Assets		$	26,693,620			$	326,993			$	(501,063	)		$	(2,428,099	)		$	24,091,451			$	296,500			$	(330,000	)		$	24,057,951
Liabilities and Stockholders’ Equity
Total deposits			21,824,990				—				—				(1,756,750	)(4)			20,068,240				—				—				20,068,240
Subordinated Debt			366,369				—				—				(37,000	)(5)			329,369				296,500				(329,369	)			296,500
Other borrowings			665,655				—				—				(634,349	)(6)			31,306				—				—				31,306
Other liabilities			287,396				—				—				—				287,396				—				—				287,396
Total Liabilities			23,144,410				—				—				(2,428,099	)			20,716,311				296,500				(329,369	)			20,683,442
Total Stockholders’ Equity			3,549,210				326,993				(501,063	)(2)			—				3,375,140				—				(631	)			3,374,509
Total Liabilities & Stockholders’ Equity		$	26,693,620			$	326,993			$	(501,063	)		$	(2,428,099	)		$	24,091,451			$	296,500			$	(330,000	)		$	24,057,951

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($ in thousands, except per share data)		June 30, 2025				Common Equity Offering				HTM Transfer to AFS (1)				Balance Sheet Repositioning (3)				Pro Forma June 30, 2025				Notes Offering (10)				Redemption of 2028 Notes (11)				Pro Forma Adjusted
Consolidated Regulatory Capital
CET1 Capital			2,551,006				326,993				—				(606,729	)(7)			2,271,270				—				—				2,271,270
Tier 1 Capital			2,551,006				326,993				—				(606,729	)(7)			2,271,270				—				—				2,271,270
Total Risk-Based Capital			2,977,454				326,993				—				(643,729	)(8)			2,660,718				300,000				(132,000	)			2,828,718
Risk Weighted Assets			20,646,324				—				—				(943,205	)(9)			19,703,119				—				—				19,703,119
Assets for Leverage Ratio			25,606,135				326,993				(501,063	)(2)			(2,428,099	)			23,003,966				—				—				23,003,966
Regulatory CRE			7,983,820				—				—				—				7,983,820				—				—				7,983,820
Tier 1 Leverage Ratio			10.0	%															9.9	%											9.9	%
CET1 Ratio			12.4	%															11.5	%											11.5	%
Total Risk-Based Capital Ratio			14.4	%															13.5	%											14.4	%
Regulatory CRE / Total Risk-Based Capital Ratio			268.1	%															300.1	%											282.2	%

(1) Investment securities transferred from held-to-maturity to available-for-sale valued as of June 30, 2025.

(2) Represents change in accumulated other comprehensive loss due to transfer of investment securities from held-to-maturity to available-for-sale.

(3) Reflects the sale of available-for-sale investment securities in the Investment Securities Transaction and the redemption of the Spirit Notes.

(4) Assumes that a portion of proceeds from sale of available-for-sale securities are used to redeem brokered deposits.

(5) Redemption and repayment in full of the Spirit Notes was effective on July 31, 2025.

(6) Assumes that a portion of proceeds from sale of available-for-sale securities are used to pay down wholesale borrowings.

(7) Includes total after-tax, realized loss on securities available-for-sale sold in the Investment Securities Transaction, assuming an estimated 24.3% tax rate.

(8) Includes total after-tax, realized loss on securities available-for-sale sold in the Investment Securities Transaction and the impact of the redemption of the Spirit Notes.

(9) Net impact of divested securities, which assumes an average risk weight of 32.9%.

(10) Assumes the issuance of Notes with an aggregate principal amount of $300 million, an underwriting discount of 1%, and $500 thousand of pre-tax offering expenses.

(11) Assumes the redemption and repayment in full of the 2028 Notes including $631 thousand in unamortized issuance costs, for which we anticipate delivering a redemption notice following this offering, with such redemption expected to be effective on October 1, 2025.

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CAPITALIZATION

The following table sets forth our capitalization as of June 30, 2025:

• on an actual basis;

• on a pro forma basis to give effect to the Common Equity Offering, the Investment Securities Transaction, and the Redemption of the Spirit Notes; and

• on a pro forma as adjusted basis to give effect to the issuance and sale of the Notes in this offering (after deducting the underwriting discount and estimated offering expenses) and the redemption of all of the 2028 Notes. As discussed under “Use of Proceeds” above, we may determine not to redeem the 2028 Notes or to redeem only a portion of the 2028 Notes.

This table is unaudited and should be read in conjunction with, and is qualified in its entirety by reference to, the information appearing under “Use of Proceeds” and under “Unaudited Pro Forma Financial Information” appearing elsewhere in this prospectus supplement, as well as our historical financial statements and related notes that are incorporated by reference into this prospectus supplement.

		As of June 30, 2025
($ in thousands, except share data)		Actual				Pro Forma				Pro Forma, as Adjusted
Cash and cash equivalents		$	644,462			$	607,462			$	573,962
Liabilities:
Deposits			21,824,990				20,068,240				20,068,240
Other borrowings (1)			665,655				31,306				31,306
Spirit Notes			37,000				—				—
2028 Notes			329,369				329,369				—
Subordinated notes offered hereby			—				—				296,500	(2)
Other liabilities			287,396				287,396				287,396
Total Liabilities		$	23,144,410			$	20,716,311			$	20,683,442
Stockholders’ equity:
Common stock, Class A, $0.01 par value; 350,000,000 shares authorized at June 30, 2025 and; 125,996,248 shares issued and outstanding at June 30, 2025		$	1,260			$	1,447			$	1,447
Surplus			2,518,286				2,845,092				2,845,092
Undivided profits			1,410,564				803,835				803,204
Accumulated other comprehensive loss			(380,900	)			(275,234	)			(275,234	)
Total stockholders’ equity		$	3,549,210			$	3,375,140			$	3,374,509
Total liabilities and stockholders’ equity		$	26,693,620			$	24,091,451			$	24,057,951

(1) Excludes the Spirit Notes and the 2028 Notes.

(2) Represent the aggregate principal amount of the Notes, reduced by the underwriting discount of 1.0% and estimated offering expenses of $500 thousand.

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DESCRIPTION OF NOTES

We will issue the Notes under a Subordinated Indenture between Simmons, as the issuer, and Wilmington Trust, National Association, as trustee (the “Trustee”), dated March 26, 2018 (the “Base Indenture”), as supplemented by a Second Supplemental Indenture between Simmons and the Trustee, to be dated as of the issue date (the “Second Supplemental Indenture”). We refer to the Base Indenture, as supplemented by the Second Supplemental Indenture, as the “Indenture.” You may request a copy of the Indenture from us as described under “Where You Can Find More Information.” We have summarized the material terms of the Indenture and the Notes below, but the summary does not purport to be complete and is subject to and qualified in its entirety by reference to the Indenture and the Notes. The following description of the terms of the Indenture and the Notes supplements and, to the extent inconsistent therewith, replaces and supersedes the description of the general terms and provisions of the subordinated debt securities in the accompanying prospectus.

You should read the Indenture and the Notes because they, and not this description, define your rights as holders of the Notes. For purposes of this section, references to “Simmons,” “we,” “us” and “our” include only Simmons First National Corporation and not any of its subsidiaries.

General

The Notes will be unsecured and subordinated obligations of Simmons and will be issued as a series of debt securities under the Indenture in an initial aggregate principal amount of $    million. The Notes are not guaranteed by Simmons Bank or any of our other subsidiaries or affiliates, or any other person. We may, from time to time, without notice to or the consent of the holders of the Notes, create and issue additional notes ranking equally with the Notes and with identical terms in all respects (or in all respects except for the offering price, the payment of interest accruing prior to the issue date of such additional notes or except for the first payment of interest following the issue date of such additional notes); provided, that a separate CUSIP number will be issued for any such additional notes unless such additional notes are fungible with the Notes for U.S. federal income tax purposes, subject to the procedures of The Depository Trust Company (with its successors, “DTC”).

The Notes will mature on    , 2035 (the “Maturity Date”), unless previously redeemed or otherwise accelerated. Payment of principal on the Notes may be accelerated only in the case of certain events of bankruptcy or insolvency. See “— Events of Default; Acceleration of Payment; Limitation on Suits.”

Beginning with the interest payment date of    , 2030, and on any interest payment date thereafter, we may, at our option, subject to obtaining the prior approval of the Federal Reserve (or any successor bank regulatory agency) to the extent such approval is then required under the rules of the Federal Reserve (“Federal Reserve Approval”), redeem the Notes, in whole or in part, at a price equal to 100% of the principal amount of the Notes to be redeemed plus any accrued and unpaid interest to, but excluding, the redemption date. The Notes may not be redeemed by us prior to    , 2030, except that we may, at our option, subject to Federal Reserve Approval, redeem the Notes in whole, but not in part, prior to maturity upon the occurrence of a “Tax Event” or a “Tier 2 Capital Event” (as such terms are defined in the Indenture) or if we are required to register as an investment company pursuant to the Investment Company Act of 1940, as amended, in each case, at a price equal to 100% of the principal amount of the Notes to be redeemed plus any accrued and unpaid interest to, but excluding, the redemption date. Any partial redemption will be made in accordance with the applicable procedures of DTC. See “— Redemption.”

The Notes are not convertible into, or exchangeable for, equity securities, other securities or assets of Simmons or its subsidiaries. There is no sinking fund for the Notes. Except as described below under“— Clearance and Settlement,” the Notes will be represented by one or more global certificates deposited with or on behalf of DTC and registered in the name of Cede & Co. or another nominee of DTC. The Notes will be issued and may be transferred only in minimum denominations of $1,000 and integral multiples of $1,000 in excess thereof in book-entry form only. See “— Clearance and Settlement.”

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As a bank holding company, our ability to make payments on the Notes will depend primarily on the receipt of interests and other distributions from Simmons Bank. There are various regulatory restrictions on the ability of Simmons Bank to pay dividends or make other distributions to us. See “Risk Factors — Payments on the Notes will depend on receipt of dividends and distributions from our subsidiaries” and “Risk Factors — Regulatory guidelines may restrict our ability to pay the principal of, and accrued and unpaid interest on, the Notes, regardless of whether we are the subject of an insolvency proceeding” in this prospectus supplement.

Delivery of reports, information and documents (including, without limitation, reports contemplated in this section) to the Trustee is for information purposes only, and the Trustee’s receipt thereof shall not constitute actual or constructive notice of any information contained therein or determinable from information contained therein, including our compliance with covenants under the Indenture and the Notes, as to which the Trustee is entitled to rely exclusively on officers’ certificates.

No recourse will be available for the payment of principal of, or interest on, any Note, for any claim based thereon, or otherwise in respect thereof, against any shareholder, employee, officer or director, as such, past, present or future, of Simmons or any successor entity. Neither the Indenture nor the Notes contain any covenants or restrictions restricting the incurrence of debt, deposits or other liabilities by us or by our subsidiaries. The Indenture and the Notes contain no financial covenants and do not restrict us from paying dividends, selling assets, making investments or issuing or repurchasing other securities, and do not contain any provision that would provide protection to the holders of the Notes against a sudden and dramatic decline in our credit quality resulting from a merger, takeover, recapitalization or similar restructuring or any other event involving us or our subsidiaries that may adversely affect our credit quality.

The Notes are not savings accounts, deposits or other obligations of Simmons Bank or any of our non-bank subsidiaries and are not insured or guaranteed by the FDIC or any other governmental agency or public or private insurer. The Notes are solely obligations of Simmons and are neither obligations of, nor guaranteed by, any of our subsidiaries.

We do not intend to apply for the listing of the Notes on any securities exchange or the quotation of the Notes on any quotation system.

Interest

From and including the date of original issuance to, but excluding,   , 2030, or the date of earlier redemption (the “fixed rate period”), the Notes will bear interest at an initial rate of   % per annum, payable semi-annually in arrears on    and    of each year (each, a “fixed rate interest payment date”), commencing on    , 2026. The last fixed rate interest payment date for the fixed rate period will be    , 2030.

From and including    , 2030 to, but excluding, the Maturity Date or the date of earlier redemption (the “floating rate period”), the Notes will bear interest at a floating rate per annum equal to the Benchmark rate (which is expected to be Three-Month Term SOFR) plus    basis points for each quarterly interest period during the floating rate period, payable quarterly in arrears on    ,    ,     and    of each year (each, a “floating rate interest payment date,” and, together with the fixed rate interest payment dates, the “interest payment dates”), commencing on    , 2031. Notwithstanding the foregoing, if the Benchmark rate is less than zero, the Benchmark rate shall be deemed to be zero.

For the purpose of calculating the interest on the Notes for each interest period during the floating rate period when the Benchmark is Three-Month Term SOFR, “Three-Month Term SOFR” means Term SOFR for a tenor of three months that is published by the Term SOFR Administrator at the Reference Time for any floating rate interest period, as determined by the calculation agent after giving effect to the Three-Month Term SOFR Conventions. See “Calculation Agent.”

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The following definitions apply to the foregoing definition of Three-Month Term SOFR:

“Benchmark” means, initially, Three-Month Term SOFR; provided that, if the calculation agent determines on or prior to the Reference Time for any floating rate interest period that a Benchmark Transition Event and its related Benchmark Replacement Date have occurred with respect to Three-Month Term SOFR or the then-current Benchmark, then “Benchmark” means the applicable Benchmark Replacement for such floating rate interest period and any subsequent floating rate interest periods.

“Corresponding Tenor” means (i) with respect to Term SOFR, three months, and (ii) with respect to a Benchmark Replacement, a tenor (including overnight) having approximately the same length (disregarding business day adjustment) as the applicable tenor for the then-current Benchmark.

“Federal Reserve Bank of New York’s Website” means the website of the Federal Reserve Bank of New York (the “FRBNY”) at http://www.newyorkfed.org, or any successor source. The foregoing Internet website is an inactive textual reference only, meaning that the information contained on the website is not part of this prospectus supplement or the accompanying prospectus or incorporated by reference herein or therein.

“Reference Time” with respect to any determination of the Benchmark means (i) if the Benchmark is Three-Month Term SOFR, the time determined by the calculation agent after giving effect to the Three-Month Term SOFR Conventions, and (ii) if the Benchmark is not Three-Month Term SOFR, the time determined by the calculation agent after giving effect to the Benchmark Replacement Conforming Changes.

“Relevant Governmental Body” means the Federal Reserve and/or the FRBNY, or a committee officially endorsed or convened by the Federal Reserve and/or the FRBNY or any successor thereto.

“SOFR” means the secured overnight financing rate published by the FRBNY, as the administrator of the Benchmark (or any successor administrator), on the Federal Reserve Bank of New York’s website.

“Term SOFR” means the forward-looking term rate for the applicable Corresponding Tenor based on SOFR as published by the Term SOFR Administrator.

“Term SOFR Administrator” means CME Group Benchmark Administration Limited (CBA) (or a successor administrator of Three-Month Term SOFR selected by the calculation agent in its reasonable discretion).

“Three-Month Term SOFR Conventions” means any determination, decision, or election with respect to any technical, administrative, or operational matter (including with respect to the manner and timing of the publication of Three-Month Term SOFR, or changes to the definition of “interest period,” timing and frequency of determining Three-Month Term SOFR with respect to each interest period and making payments of interest, rounding of amounts or tenors, and other administrative matters) that the calculation agent determines may be appropriate to reflect the use of Three-Month Term SOFR as the Benchmark in a manner substantially consistent with market practice (or, if the calculation agent determines that adoption of any portion of such market practice is not administratively feasible or if the calculation agent determines that no market practice for the use of Three-Month Term SOFR exists, in such other manner as the calculation agent determines is reasonably necessary).

The terms “Benchmark Replacement Conforming Changes,” “Benchmark Replacement Date,” “Benchmark Replacement,” “Benchmark Replacement Adjustment,” and “Benchmark Transition Event” have the meanings set forth under the heading “— Effect of Benchmark Transition Event.”

Notwithstanding the foregoing paragraphs related to the determination of interest, if the calculation agent determines on or prior to the relevant Reference Time that a Benchmark Transition Event and its related Benchmark Replacement Date (each as defined below) have occurred with respect to Three-Month Term SOFR, then the provisions set forth under the heading “— Effect of Benchmark Transition Event,” which we refer to as

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the “benchmark transition provisions,” will thereafter apply to all determinations of the interest rate on the Notes for each interest period during the floating rate period. In accordance with the benchmark transition provisions, after a Benchmark Transition Event and its related Benchmark Replacement Date have occurred, the interest rate on the Notes for each interest period during the floating rate period will be an annual rate equal to the Benchmark Replacement (as defined below) plus    basis points.

Absent manifest error, the calculation agent’s determination of the interest rate for an interest period for the Notes will be binding and conclusive on you and the Trustee. The calculation agent will promptly provide its determination of any interest rate during the floating rate period to the Trustee and to us.

Interest shall be calculated on the basis of a 360-day year consisting of twelve 30-day months during the fixed rate period and, during the floating rate period, on the basis of a 360-day year and the actual number of days elapsed. Dollar amounts resulting from that calculation will be rounded to the nearest cent, with one-half cent being rounded upward.

Interest on the Notes, subject to certain exceptions, will accrue during the applicable interest period. When we use the term “interest period,” we mean the period from and including the immediately preceding interest payment date in respect of which interest has been paid or duly provided for or, if no interest has been paid or duly provided for, from and including the date of issuance of the Notes to, but excluding, the applicable interest payment date or the Maturity Date or date of earlier redemption, if applicable. If a fixed rate interest payment date or the Maturity Date falls on a day that is not a business day, then the interest payment or the payment of principal and interest at maturity will be postponed to the next succeeding business day, but the payments made on such dates will be treated as being made on the date that the payment was first due and the holders of the Notes will not be entitled to any further interest or other payments in respect thereof. However, if a floating rate interest payment date falls on a day that is not a business day, then such floating rate interest payment date will be postponed to the next succeeding business day unless such day falls in the next succeeding calendar month, in which case such floating rate interest payment date will be accelerated to the immediately preceding business day, and, in each such case, the amounts payable on such business day will include interest accrued to, but excluding, such business day.

Interest on each Note will be payable to the person in whose name such Note is registered on the fifteenth day immediately preceding the applicable interest payment date, whether or not such day is a business day. Any interest which is payable, but is not punctually paid or duly provided for, on any interest payment date shall cease to be payable to the holder on the relevant record date by virtue of having been such holder, and such defaulted interest may be paid by us to the person in whose name the Notes are registered at the close of business on a special record date for the payment of defaulted interest. However, interest that is paid on the Maturity Date will be paid to the person to whom the principal is payable. Interest will be payable by wire transfer in immediately available funds in U.S. dollars to DTC or its nominee or, at our option in the event the Notes are not represented by Global Notes (as defined below), by check mailed to the address of the person specified for payment in the preceding sentences.

If any of the foregoing provisions concerning the calculation of the interest rate and interest payments during the floating rate period are inconsistent with any of the Three-Month Term SOFR Conventions determined by the calculation agent, then the relevant Three-Month Term SOFR Conventions will apply. Furthermore, if the calculation agent determines that a Benchmark Transition Event and its related Benchmark Replacement Date have occurred with respect to Three-Month Term SOFR at any time when any of the Notes are outstanding, then the foregoing provisions concerning the calculation of the interest rate and interest payments during the floating rate period will be modified in accordance with the benchmark transition provisions.

When we use the term “business day,” we mean any day, other than a Saturday or Sunday, that is neither a legal holiday nor a day on which banking institutions in the City of New York or any place of payment are

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authorized or required by law, regulation, or executive order to close; provided, that, when used in connection with an amount that bears interest at a rate based on SOFR or Term SOFR or any direct or indirect calculation or determination of SOFR or Term SOFR, the term “business day” means any such day that is also a U.S. Government Securities Business Day. “U.S. Government Securities Business Day” means any day except for (a) a Saturday, (b) a Sunday or (c) a day on which the Securities Industry and Financial Markets Association recommends that the fixed income departments of its members be closed for the entire day for purposes of trading in United States government securities.

Ranking; Subordination

The Notes will be unsecured, subordinated obligations of Simmons. The Notes will rank equal in right of payment and upon our liquidation with any of our future indebtedness the terms of which provide that such indebtedness ranks equally with the Notes and senior in right of payment and upon our liquidation to any of our future indebtedness the terms of which provide that such indebtedness ranks junior in right of payment to the Notes. Our obligation to make any payment on account of the Notes will be subordinated and junior to our Senior Indebtedness (as defined in the Indenture and described below).

The Notes will not be guaranteed by any of our subsidiaries, including Simmons Bank, which is our principal subsidiary. The Notes will be effectively subordinated to our future secured indebtedness to the extent of the value of the collateral securing such indebtedness and structurally subordinated to the existing and future indebtedness of our subsidiaries, including without limitation Simmons Bank’s depositors, liabilities to general creditors and liabilities arising in the ordinary course of business or otherwise, which means that such creditors generally will be paid from those subsidiaries’ assets before holders of the Notes would have any claims to those assets.

The Indenture and the Notes do not limit the amount of Senior Indebtedness, secured indebtedness, or other liabilities having priority over, or ranking equally with, the Notes that we or our subsidiaries may hereafter incur. As of June 30, 2025, Simmons’ outstanding indebtedness and other liabilities totaled approximately $23.1 billion, which includes approximately $21.8 billion of deposits and $617.8 million of FHLB advances that rank structurally senior to the Notes, $16.5 million of other long-term debt that ranks senior to the Notes and $366.4 million of outstanding subordinated debt securities that rank equal in right of payment to the Notes. On July 31, 2025, we redeemed $37.0 million of our outstanding Spirit Notes. We intend to use the net proceeds from this offering to repay our outstanding $330 million of the 2028 Notes and for general corporate purposes; however, we may determine not to redeem the 2028 Notes or to redeem only a portion of the 2028 Notes.

“Senior Indebtedness” means, without duplication, the principal, premium, if any, unpaid interest (including interest accruing on or after the filing of any petition in bankruptcy or for reorganization relating to Simmons, whether or not a claim for post-filing interest is allowed in such proceeding), fees, charges, expenses, reimbursement and indemnification obligations, and all other amounts payable under or in respect of the following indebtedness of Simmons, whether any such indebtedness exists as of the date of the Indenture or is created, incurred or assumed after such date:

• all obligations for borrowed money;

• all obligations evidenced by debentures, debt securities or other similar instruments;

• all obligations in respect of letters of credit, security purchase facilities or bankers acceptances or similar instruments (or reimbursement obligations with respect thereto);

• all obligations to pay the deferred purchase price of property or services, except trade accounts payable arising in the ordinary course of business;

• all indebtedness of others guaranteed by Simmons or any of its subsidiaries or for which Simmons or any of its subsidiaries is legally responsible or liable (whether by agreement to purchase indebtedness of, or to supply funds or to invest in, others);

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• indebtedness secured by any mortgage, pledge, lien, charge, encumbrance or any security interest existing on property owned by Simmons but excluding any obligations of Simmons which are required (as opposed to elected) to be treated as capitalized leases under GAAP;

• obligations associated with derivative products including, but not limited to, interest rate and currency future or exchange contracts, foreign exchange contracts, swap agreements (including interest rate and foreign exchange rate swap agreements), cap agreements, floor agreements, collar agreements, options, interest rate future or option contracts, commodity contracts, and similar arrangements;

• purchase money and similar obligations;

• obligations to general creditors of Simmons;

• a deferred obligation of, or any such obligation, directly or indirectly guaranteed by, Simmons which obligation is incurred in connection with the acquisition of any business, properties or assets not evidenced by a note or similar instrument given in connection therewith;

• interest or obligations in respect of any of the foregoing accruing after the commencement of insolvency or bankruptcy proceedings; and

• any renewals, amendments, deferrals, supplements, extensions, refundings or replacements of any of the foregoing.

With respect to the Notes, Senior Indebtedness excludes:

• any such indebtedness, obligation or liability referred to above as to which, in the instrument creating or evidencing the same or pursuant to which the same is outstanding, it is provided that such indebtedness, obligation or liability is not superior in right of payment to the Notes, or ranks pari passu with the Notes;

• any such indebtedness, obligation or liability which is subordinated to indebtedness of Simmons to substantially the same extent as, or to a greater extent than, the Notes are subordinated;

• any indebtedness to a subsidiary of Simmons;

• any trade account payables in the ordinary course of business; and

• the Notes.

Notwithstanding the foregoing, and for the avoidance of doubt, if the Federal Reserve (or other applicable regulatory agency or authority) promulgates any rule or issues any interpretation that defines general creditor(s), the main purpose of which is to establish criteria for determining whether the subordinated debt of a financial or bank holding company is to be included in its capital, then the term “general creditors” as used in the definition of “Senior Indebtedness” in the Indenture will have the meaning as described in that rule or interpretation.

Upon the liquidation, dissolution, winding up, or reorganization of Simmons, we must pay to the holders of all Senior Indebtedness the full amounts of principal of, premium, interest and any other amounts owing on, that Senior Indebtedness before any payment is made on the Notes. If, after we have made those payments on our Senior Indebtedness there are amounts available for payment on the Notes, then we may make any payment on the Notes.

Because of the subordination provisions and the obligation to pay Senior Indebtedness described above, in the event of the insolvency of Simmons, holders of the Notes may recover less ratably than holders of the Senior Indebtedness and other creditors of Simmons. With respect to the assets of a subsidiary of ours, our creditors (including holders of the Notes) are structurally subordinated to the prior claims of creditors of such subsidiary, except to the extent that we may be a creditor with recognized claims against such subsidiary.

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Subject to the terms of the Indenture, if the Trustee or any holder of any of the Notes receives any payment or distribution of our assets in contravention of the subordination provisions applicable to the Notes before all Senior Indebtedness is paid in full in cash, property or securities, including by way of set-off or any such payment or distribution that may be payable or deliverable by reason of the payment of any other of our indebtedness being subordinated to the payment of the Notes, then such payment or distribution will be held in trust for the benefit of holders of Senior Indebtedness or their representatives to the extent necessary to make payment in full in cash or payment satisfactory to the holders of Senior Indebtedness of all unpaid Senior Indebtedness.

No Additional Amounts

In the event that any payment on the Notes is subject to withholding of any U.S. federal income tax or other tax or assessment (whether as a result of a change in law or otherwise), we will not pay additional amounts with respect to such tax or assessment. For a discussion relating to certain U.S. federal income tax consequences of the ownership and disposition of the Notes, see “Material U.S. Federal Income Tax Considerations” in this prospectus supplement.

Redemption

The Notes are not subject to redemption or prepayment at the option of the holders.

We may, at our option, beginning with the interest payment date of    , 2030, but not prior thereto (except upon the occurrence of certain events specified below), and on any interest payment date thereafter, redeem the Notes, in whole or in part, from time to time, subject to obtaining the Federal Reserve Approval, at a price equal to 100% of the principal amount of the Notes being redeemed plus interest that is accrued and unpaid to, but excluding, the date of redemption.

The Notes may not otherwise be redeemed prior to the Maturity Date, except that we may also, at our option, redeem the Notes, in whole, but not in part, subject to obtaining the Federal Reserve Approval, at a redemption price equal to 100% of the principal amount of the Notes being redeemed plus interest that is accrued and unpaid to, but excluding, the date of redemption, at any time, including before    , 2030, upon the occurrence of:

• a “Tax Event,” defined in the Indenture to mean the receipt by Simmons of an opinion of independent tax counsel to the effect that as a result of (a) an amendment to or change (including any announced prospective amendment or change) in any law or treaty, or any regulation thereunder, of the United States or any of its political subdivisions or taxing authorities; (b) a judicial decision, administrative action, official administrative pronouncement, ruling, regulatory procedure, regulation, notice or announcement, including any notice or announcement of intent to adopt or promulgate any ruling, regulatory procedure or regulation (any of the foregoing, an “administrative or judicial action”); or (c) an amendment to or change in any official position with respect to, or any interpretation of, an administrative or judicial action or a law or regulation of the United States that differs from the previously generally accepted position or interpretation, in each case, which change or amendment or challenge becomes effective or which pronouncement, or decision or challenge is announced on or after the original issue date of the Notes, there is more than an insubstantial risk that interest payable by us on the Notes is not, or, within 90 days of the date of such opinion, will not be, deductible by us, in whole or in part, for United States federal income tax purposes;

• a “Tier 2 Capital Event,” defined in the Indenture to mean Simmons’ good faith determination that, as a result of (a) any amendment to, or change in, the laws, rules or regulations of the United States (including, for the avoidance of doubt, any agency or instrumentality of the United States, including the Federal Reserve and other federal bank regulatory agencies) or any political subdivision of or in the United States that is enacted or becomes effective after the original issue date of the Notes; (b) any

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proposed change in those laws, rules or regulations that is announced or becomes effective after the original issue date of the Notes; or (c) any official administrative decision or judicial decision or administrative action or other official pronouncement interpreting or applying those laws, rules, regulations, policies or guidelines with respect thereto that is announced after the original issue date of the Notes, there is more than an insubstantial risk that we will not be entitled to treat the Notes then outstanding as “Tier 2 Capital” (or its equivalent) for purposes of the capital adequacy rules or regulations of the Federal Reserve (or, as and if applicable, the capital adequacy rules or regulations of any successor appropriate federal banking agency) as then in effect and applicable to us, for so long as any Notes are outstanding; or

• Simmons becoming required to register as an investment company pursuant to the Investment Company Act of 1940, as amended.

In the event of any redemption of the Notes, we will deliver or cause to be delivered a notice of redemption (which notice may be conditional in our discretion on one or more conditions precedent, and the redemption date may be delayed until such time as any or all of such conditions have been satisfied or revoked by us if we determine that such conditions will not be satisfied) to each holder of Notes not less than 10 business days nor more than 60 calendar days prior to the redemption date.

Any partial redemption will be made in accordance with DTC’s applicable procedures among all of the holders of the Notes. If any Note is to be redeemed in part only, the notice of redemption relating to such Note shall state the portion of the principal amount thereof to be redeemed. A replacement Note in principal amount equal to the unredeemed portion thereof will be issued in the name of the holder thereof upon cancellation of the original Note.

Events of Default; Acceleration of Payment; Limitation on Suits

The Notes and Indenture provide for only limited events upon which the principal of the Notes may be accelerated. These events are:

• a court having jurisdiction in the premises shall enter a decree or order for relief in respect of us or the Material Subsidiary in an involuntary case under any applicable bankruptcy, insolvency or other similar law now or hereafter in effect, or appointing a receiver, liquidator, assignee, custodian, trustee, sequestrator (or similar official) of us or any Material Subsidiary or for any substantial part of their respective property, or ordering the winding-up or liquidation of its affairs and such decree or order shall remain unstayed and in effect for a period of 60 consecutive days; or

• we or the Material Subsidiary shall commence a voluntary case under any applicable bankruptcy, insolvency or other similar law now or hereafter in effect, or shall consent to the entry of an order for relief in an involuntary case under any such law, or shall consent to the appointment of or taking possession by a receiver, liquidator, assignee, trustee, custodian, sequestrator (or similar official) of the Company or the Material Subsidiary or for any substantial part of their respective property, or shall make any general assignment for the benefit of creditors.

A “Material Subsidiary” means Simmons Bank or any successor thereof or any of our subsidiaries that is a depository institution and that has consolidated assets equal to 80% or more of our consolidated assets.

If any of the foregoing occurs and is continuing, the principal, premium (if any) and interest in respect of the Notes shall automatically, and without any declaration or other action on the part of the Trustee or any Holder, become immediately due and payable.

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The Notes and Indenture provide for a limited number of other events of default, which do not permit acceleration of the payment of principal, premium (if any) and interest in respect of the Notes, including:

• our default in the payment of any interest upon the Notes, when such interest becomes due and payable, and continuance of such default for a period of 30 days;

• our default in the payment of the principal of (or premium, if any on) the Notes with respect to any of the Notes when due, either at maturity, upon redemption, by declaration or otherwise; or

• our default in the performance, or breach, of any covenant or agreement in the Indenture applicable to us, and continuance of such default or breach for a period of 90 days after there has been given, by registered or certified mail, to us by the Trustee or to us and the Trustee by the holders of at least 25% in aggregate principal amount of the outstanding Notes a written notice specifying such default or breach and requiring it to be remedied and stating that such notice is a “Notice of Default” under the Indenture.

There is no right of acceleration in the case of a default in the payment of principal of or interest on the Notes or in our non-performance of any other obligation under the Notes or the Indenture. However, if any of the foregoing additional events of default occurs, then the Trustee may, subject to certain limitations and conditions and the subordination provisions of the Indenture, exercise all remedies otherwise permitted by applicable law.

If we default in our obligation to pay any interest on the Notes when due and payable and such default continues for a period of 30 days, or if we default in our obligation to pay the principal of (or premium, if any) with respect to any of the Notes when due, either at maturity, upon redemption, by declaration or otherwise, or if we breach any covenant or agreement contained in the Indenture and such breach continues for a period of 90 days after the date on which written notice specifying such failure and requiring us to remedy the same shall have been given to us, then the Trustee may, subject to certain limitations and conditions, seek to enforce its rights and the rights of the holders of Notes of the performance of any covenant or agreement in the Indenture.

The Indenture provides that the Trustee will be under no obligation to exercise any of its rights or powers under the Indenture at the request or direction of any of the holders of Notes unless such holders shall have offered to the Trustee indemnity or security satisfactory to it against the costs, expenses and liabilities which may be incurred by it in complying with such request or direction.

Subject to certain provisions, the holders of a majority in principal amount of the outstanding Notes will have the right to direct the time, method, and place of conducting any proceeding for any remedy available to the Trustee or exercising any trust or power conferred on the Trustee with respect to the Notes. However, the Trustee may refuse to follow any direction that conflicts with law or the Indenture or that may involve the Trustee in personal liability. In addition, the Trustee may take any other action it deems proper that is not inconsistent with any such direction received from the holders of the Notes.

No holder of Notes will have any right to institute any proceeding, judicial or otherwise, with respect to the Indenture or a Note, or for the appointment of a receiver or trustee, or for any other remedy under the Indenture, unless:

• such holder has previously given written notice to the Trustee of a continuing event of default with respect to the Notes;

• the holders of not less than 25% in aggregate principal amount of the outstanding Notes have made written request to the Trustee to institute proceedings in respect of such event of default in its own name as Trustee under the Indenture;

• such holder or holders have offered to the Trustee reasonable indemnity satisfactory to the Trustee against the costs, expenses and liabilities to be incurred in compliance with such request;

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• the Trustee for 60 days after its receipt of such notice, request and offer of reasonable security and indemnity has failed to institute any such proceeding; and

• no direction inconsistent with such written request has been given to the Trustee during such 60-day period by the holders of a majority in principal amount of the outstanding Notes.

In any event, the Indenture provides that no holder of Notes shall have any right in any manner whatever by virtue of, or by availing of, any provision of the Indenture to affect, disturb or prejudice the rights of any other of such holders, or to obtain or to seek to obtain priority or preference over any other of such holders or to enforce any right under the Indenture, except in the manner provided in the Indenture and for the equal and ratable benefit of all holders of Notes.

The Indenture requires the Trustee to notify the holders of the Notes within 90 days regarding the existence of any default actually known to the Trustee, unless the default has been cured or waived. In addition, in the case of a default in payment of principal of or interest on any Note, the Trustee may withhold notice of a default if and so long as the Trustee and/or responsible officers, the board of directors or certain committees of the board of directors in good faith determines that withholding the notice is in the interests of the holders of the Notes. For purposes of these requirements, a “default” means any event which is, or after notice or lapse of time or both would become, an event of default under the Indenture with respect to the Notes.

We are required to deliver to the Trustee, within 120 days after the end of each of our fiscal years ending after the issue date of the Notes, a written statement from our applicable officers regarding whether we have fulfilled all of our obligations under the Indenture throughout the year and specifying any known default and its status.

Modification and Waiver

Except as set forth below, modification and amendment of the Indenture, or entry into a supplemental indenture applicable to the Notes may be made only when authorized by our board of directors and with the consent of the holders of not less than a majority in principal amount of the Notes affected by such supplemental indenture, voting together as a single class.

Notwithstanding the foregoing, no modification or amendment of the Indenture as applicable to the Notes may:

• extend the fixed maturity of the Notes, or reduce the principal amount thereof or premium, if any, or reduce the rate or extend the time of payment of interest thereon, without the consent of the holder of each Note so affected;

• reduce the percentage in principal amount of outstanding Notes that is required for any supplemental indenture without the consent of the holders of all Notes then outstanding;

• modify the subordination provision in a manner adverse to the holders of any Note without the consent of the holders of all Notes then outstanding;

• waive a redemption payment with respect to the Notes without the consent of the holders of all Notes then outstanding; or

• modify such provisions with respect to modification and waiver without the consent of the holders of all Notes then outstanding.

In addition, the holders of a majority in aggregate principal amount of the outstanding Notes may, on behalf of all holders of Notes, waive compliance by us with certain terms, conditions and provisions of the Indenture, as well as any past default and/or the consequences of default, other than any default in the payment of principal or interest or any breach in respect of a covenant or provision that cannot be modified or amended without the consent of the holder of each outstanding Note.

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In addition, we and the Trustee may modify and amend the Indenture without the consent of any holders of Notes for any of the following purposes:

• to evidence the succession of another corporation to Simmons and provide for the successor’s assumption of the covenants, agreements and obligations under the Indenture and the Notes issued thereunder;

• to add further covenants, restrictions, conditions or provisions as our board of directors considers to be for the protection of the holders of the Notes, and to make the occurrence, or the occurrence and continuance, of a default in any of such additional covenants, restrictions, conditions or provisions an Event of Default permitting the enforcement of all or any of the remedies provided under the Indenture, with such period of grace and subject to such conditions as such supplemental indenture may provide;

• to add or change any of the provisions of the Indenture to provide that the Notes may be registrable as to principal, to change or eliminate any restrictions on the payment of principal of or any premium or interest on Bearer Securities, to permit Bearer Securities to be issued in exchange for Registered Securities, to permit Bearer Securities to be issued in exchange for Bearer Securities of other authorized denominations or to permit or facilitate the issuance of Notes in uncertificated form; provided, that no such action shall adversely affect the interests of the holders of the Notes or any related coupons in any material respect;

• to modify, eliminate or add provisions of the Indenture in order to effect the qualification of the applicable indenture under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”), and to add such other provisions as may be expressly permitted by the Trust Indenture Act, excluding Section 316(a)(2) thereof;

• to modify, eliminate or add to any provisions of the Indenture; provided that any such change or elimination becomes effective only when there are no outstanding debt securities or does not apply to any outstanding debt security;

• (i) to cure any ambiguity or to correct or supplement any provision in the indenture or any supplemental indenture which may be defective or inconsistent with any other provision, (ii) to convey, transfer, assign, mortgage or pledge any property to or with the trustee or (iii) to make such other provisions in regard to matters or questions arising under the Indenture; provided, that no such provision, shall adversely affect in any material respect the interests of the holders of the debt securities or any related coupons, including provisions necessary or desirable to provide for or facilitate the administration of the trusts;

• to secure any of the Notes; and

• to evidence and provide for the acceptance and appointment by a successor trustee with respect to the Notes of one or more series and to add or change any provisions of the Indenture as necessary to provide for or facilitate the administration of the trusts by more than one trustee.

The Trustee shall not be obligated to enter into any amendment or supplemental indenture, which adversely affects the Trustee’s own rights, duties or immunities under the Indenture or otherwise.

Not in limitation of the foregoing, without the consent of any holders of Notes, we and the Trustee, may amend or supplement the Indenture or the Notes (i) to conform the terms of the Indenture and the Notes to the description of the Notes in this prospectus supplement relating to the offering of the Notes or (ii) to implement any benchmark transition provisions after a Benchmark Transition Event and its related Benchmark Replacement Date have occurred (or in anticipation thereof).

The Trustee shall be entitled to receive an officer’s certificate and opinion of counsel confirming that all conditions precedent are satisfied with respect to any supplemental indenture, that such supplemental indenture is authorized and permitted and that such supplemental indenture is the legal, valid and binding obligation of Simmons, enforceable against it in accordance with its terms.

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Subject to the requirements for the holders to waive a default and to pursue a remedy with respect to the Indenture or the Notes and the rights of any holder of a Note to receive payment of principal of, premium, if any, on and interest on such Note, holders of a majority in aggregate principal amount of the Notes voting as a single class may waive compliance in a particular instance by us with any provision of the Indenture or the Note and rescind and annul such declaration and its consequences, except as otherwise stated above, but no waiver or rescission and annulment will extend to or affect any subsequent default or impair any other right.

Legal Defeasance and Covenant Defeasance

Legal Defeasance

Under the terms of the Indenture and unless as otherwise provided in a supplemental indenture, we will be deemed to have paid and will be discharged from any and all obligations in respect of the Notes on the 123rd day (or later as described below) after we have made the deposit referred to below, and the provisions of the Indenture will cease to be applicable with respect to the Notes (except for, among other matters, certain rights of the holders to receive payments of principal, premium and interest on such Notes from the trust fund, and our obligations to register the transfer of or exchange of the Notes, prepare temporary Notes, to replace stolen, lost or mutilated Notes, to maintain paying agencies and to hold funds for payment in trust, and rights, powers, trusts, duties, and immunities with respect to the Trustee) if:

• we have irrevocably deposited or caused to be deposited with the Trustee, in trust, money in an amount and/or non-callable or non-redeemable government securities that will provide funds in amount sufficient, in the opinion of a nationally recognized public accounting firm expressed in a written certification delivered to the Trustee, to pay the principal of, premium, if any, and accrued interest on the Notes at the time such payments are due or on the applicable redemption date in accordance with the terms of the Indenture;

• no default or event that after notice or lapse of time, or both, would become a default with respect to such Notes, will have occurred and be continuing on the date of such deposit, or insofar as events of default due to certain events of bankruptcy, insolvency or reorganization in respect of us are concerned, during the period ending on the 123rd day after the date of such deposit or, if longer, ending on the day following the expiration of the longest preference period applicable to Simmons with respect to such deposit;

• such defeasance or covenant defeasance does not (i) cause the Trustee to have a conflicting interest under the terms of the Indenture or the Trust Indenture Act or (ii) result in the trust arising from such deposit to constitute, unless it is qualified, a regulated investment company under the Investment Company Act of 1940, as amended;

• such defeasance or covenant defeasance shall not result in a breach or violation of, or constitute a default under, the Indenture or any other agreement or instrument to which we are a party or by which we are bound;

• such defeasance or covenant defeasance does not cause the Notes then listed on any registered national securities exchange under the Exchange Act to be delisted;

• we have delivered to the Trustee an opinion of counsel stating that (a) we have received from, or there has been published by, the Internal Revenue Service a ruling, or (b) since the date of the Indenture there has been a change in the applicable federal income tax law, to the effect that, and based thereon, holders of the debt securities will not recognize income, gain or loss for federal income tax purposes as a result of such defeasance and will be subject to federal income tax on the same amounts and in the same manner and at the same times as would have been the case if such defeasance had not occurred;

• such defeasance is effected in compliance with any terms, conditions or limitations which may be imposed on Simmons in connection with a supplemental indenture or board resolutions establishing the Notes; and

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• we shall have delivered to the Trustee an officer’s certificate and an opinion of counsel, each stating that, all conditions precedent and subsequent provided for in the Indenture relating to the defeasance have been complied with.

Covenant Defeasance

Under the terms of the Indenture and unless as otherwise provided in a supplemental indenture, we will not need to comply with certain restrictive covenants, and the provisions of the Indenture will cease to be applicable with respect to an event of default under the Notes other than an event of default due to our failure to pay the principal of or interest on the Notes when due, upon:

• the satisfaction of the conditions described in “- Legal Defeasance,” other than with respect to the sixth bullet point;

• our delivery to the Trustee of an opinion of counsel to the effect that the holders of the Notes will not recognize income, gain or loss for United States federal income tax purposes as a result of such covenant defeasance and will be subject to United States federal income tax on the same amount and in the same manner and at the same times as would have been the case if such covenant defeasance had not occurred; and

• our delivery to the Trustee of an officer’s certificate and an opinion of counsel, each stating that, all conditions precedent and subsequent provided for in the Indenture relating to the defeasance have been complied with.

If we exercise our option to omit compliance with certain provisions of the Indenture as described in the immediately preceding paragraph and the Notes are declared due and payable because of the occurrence of an event of default that remains applicable, the amount of money and/or non-callable government securities on deposit with the Trustee may not be sufficient to pay amounts due on the Notes at the time of acceleration resulting from such event of default. In such event, we will remain liable for such payments.

Satisfaction and Discharge

We may discharge our obligations under the Indenture and the Notes (except for certain surviving rights of the Trustee and our obligations in connection therewith) if: (a) all outstanding Notes and all other outstanding notes issued under the Indenture (i) have been delivered for cancellation, or (ii) (1) have become due and payable, (2) are by their terms due and payable within one year, (3) are to be called for redemption within one year under arrangements satisfactory to the Trustee for the giving of notice and redemption by the Trustee, (and in the case of clauses (1) and (3), we have irrevocably deposited or caused to be deposited with the Trustee an amount sufficient to pay and discharge the principal of  (and premium, if any) and interest on all outstanding Notes and any other sums due on the stated maturity date or redemption date, as the case may be); (b) we have paid all other sums payable by us under the Indenture; and (c) we have delivered an officer’s certificate and opinion of counsel confirming that all conditions precedent with respect to the satisfaction and discharge of the Indenture have been satisfied. Upon demand of and at our cost and expense, the Trustee will execute such instruments reasonably requested by us acknowledging the satisfaction and discharge of the Indenture with respect to the Notes.

Consolidation, Merger and Sale of Assets

The Indenture provides that we may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to any person, and we may not permit any other person to consolidate with or merge into us or to convey, transfer or lease all or substantially all of its properties and assets to us, unless:

• we are either the continuing corporation or the successor corporation is a corporation organized and existing under the laws of the United States or a state thereof or the District of Columbia and expressly assumes the due and punctual payment of the principal, premium, if any, and interest on all the Notes

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according to their tenor, and the due and punctual performance and observance of all of the covenants and conditions of the Indenture to be performed by us by supplemental indenture, executed and delivered to the Trustee by such successor corporation;

• neither we nor such successor corporation, immediately after giving effect to such merger, consolidation, sale or conveyance, will be in default in the performance of any covenant or condition under the Indenture; and

• we shall have delivered to the Trustee an officer’s certificate and an opinion of counsel, each stating that the transaction complies with the terms of the Indenture and that all conditions precedent in such Indenture provided for relating to such transaction have been complied with.

In the case of any such consolidation or merger, sale or conveyance and upon any such assumption by the successor corporation, the successor corporation shall succeed to, and be substituted for, us under the Indenture with the same effect as if it had been an original party to such Indenture. As a result, we will be released from all our liabilities and obligations under the Indenture and under the Notes issued thereunder.

Further Issuances

If no Event of Default has occurred and is continuing with respect to the Notes, we may, from time to time, without notice to or the consent of the holders of the Notes, create and issue additional notes under the Indenture ranking equally with the Notes and with identical terms in all respects (or in all respects except for the offering price, the payment of interest accruing prior to the issue date of such further notes or except for the first payment of interest following the issue date of such additional notes) in order that such additional notes may be consolidated and form a single series with the Notes and have the same terms as to status, redemption or otherwise as the Notes, subject to the procedures of DTC; provided however, that a separate CUSIP number will be issued for any such additional notes unless such additional notes are fungible with the Notes for U.S. federal income tax purposes. In addition, we may, from time to time, create and issue other series of subordinated debt securities under the Base Indenture having different terms than the Notes. The Base Indenture does not limit the amount of subordinated notes that we may issue from time to time in one or more series.

Effect of Benchmark Transition Event

If the calculation agent determines that a Benchmark Transition Event and its related Benchmark Replacement Date have occurred on or prior to the Reference Time in respect of any interest period during the floating rate period, then the Benchmark Replacement will replace the then-current Benchmark for all purposes relating to the Notes during such interest period and all subsequent interest periods. In connection with the implementation of a Benchmark Replacement, the calculation agent will have the right to make Benchmark Replacement Conforming Changes from time to time.

As used herein:

“Benchmark Replacement” means the Interpolated Benchmark with respect to the then-current Benchmark, plus the Benchmark Replacement Adjustment for such Benchmark; provided that if (i) the calculation agent cannot determine the Interpolated Benchmark as of the Benchmark Replacement Date or (ii) the then-current Benchmark is Three-Month Term SOFR and a Benchmark Transition Event and its related Benchmark Replacement Date have occurred with respect to Three-Month Term SOFR (in which event no Interpolated Benchmark with respect to Three-Month Term SOFR shall be determined), then “Benchmark Replacement” means the first alternative set forth in the order below that can be determined by the calculation agent as of the Benchmark Replacement Date:

(1) Compounded SOFR;

(2) the sum of: (a) the alternate rate that has been selected or recommended by the Relevant Governmental Body as the replacement for the then-current Benchmark for the applicable Corresponding Tenor and (b) the Benchmark Replacement Adjustment;

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(3) the sum of: (a) the ISDA Fallback Rate and (b) the Benchmark Replacement Adjustment; and

(4) the sum of (a) the alternate rate that has been selected by the calculation agent as the replacement for the then-current Benchmark for the applicable Corresponding Tenor, giving due consideration to any industry-accepted rate as a replacement for the then-current Benchmark for U.S. dollar-denominated floating rate securities at such time, and (b) the Benchmark Replacement Adjustment.

“Benchmark Replacement Adjustment” means the first alternative set forth in the order below that can be determined by the calculation agent as of the Benchmark Replacement Date:

(1) the spread adjustment, or method for calculating or determining such spread adjustment (which may be a positive or negative value or zero), that has been selected or recommended by the Relevant Governmental Body for the applicable Unadjusted Benchmark Replacement;

(2) if the applicable Unadjusted Benchmark Replacement is equivalent to the ISDA Fallback Rate, then the ISDA Fallback Adjustment; and

(3) the spread adjustment (which may be a positive or negative value or zero) that has been selected by the calculation agent, giving due consideration to any industry-accepted spread adjustment or method for calculating or determining such spread adjustment, for the replacement of the then-current Benchmark with the applicable Unadjusted Benchmark Replacement for U.S. dollar-denominated floating rate securities at such time.

“Benchmark Replacement Conforming Changes” means, with respect to any Benchmark Replacement, any technical, administrative, or operational changes (including changes to the definition of “interest period,” timing and frequency of determining rates with respect to each interest period and making payments of interest, rounding of amounts or tenors, and other administrative matters) that the calculation agent determines may be appropriate to reflect the adoption of such Benchmark Replacement in a manner substantially consistent with market practice (or, if the calculation agent determines that adoption of any portion of such market practice is not administratively feasible or if the calculation agent determines that no market practice for use of the Benchmark Replacement exists, in such other manner as the calculation agent determines is reasonably necessary).

“Benchmark Replacement Date” means the earliest to occur of the following events with respect to the then-current Benchmark:

(1) in the case of clause (1) of the definition of “Benchmark Transition Event,” the relevant Reference Time in respect of any determination;

(2) in the case of clause (2) or (3) of the definition of “Benchmark Transition Event,” the later of (a) the date of the public statement or publication of information referenced therein and (b) the date on which the administrator of the Benchmark permanently or indefinitely ceases to provide the Benchmark; or

(3) in the case of clause (4) of the definition of “Benchmark Transition Event,” the date of the public statement or publication of information referenced therein.

For the avoidance of doubt, if the event giving rise to the Benchmark Replacement Date occurs on the same day as, but earlier than, the Reference Time in respect of any determination, the Benchmark Replacement Date will be deemed to have occurred prior to the Reference Time for such determination.

“Benchmark Transition Event” means the occurrence of one or more of the following events with respect to the then-current Benchmark:

(1) if the Benchmark is Three-Month Term SOFR, we determine that the use of a forward-looking rate for a tenor of three months based on SOFR is not administratively feasible;

(2) a public statement or publication of information by or on behalf of the administrator of the Benchmark announcing that such administrator has ceased or will cease to provide the Benchmark, permanently or indefinitely, provided that, at the time of such statement or publication, there is no successor administrator that will continue to provide the Benchmark;

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(3) a public statement or publication of information by the regulatory supervisor for the administrator of the Benchmark, the central bank for the currency of the Benchmark, an insolvency official with jurisdiction over the administrator for the Benchmark, a resolution authority with jurisdiction over the administrator for the Benchmark or a court or an entity with similar insolvency or resolution authority over the administrator for the Benchmark, which states that the administrator of the Benchmark has ceased or will cease to provide the Benchmark permanently or indefinitely, provided that, at the time of such statement or publication, there is no successor administrator that will continue to provide the Benchmark; or

(4) a public statement or publication of information by the regulatory supervisor for the administrator of the Benchmark announcing that the Benchmark is no longer representative.

“Compounded SOFR” means the compounded average of SOFRs for the applicable Corresponding Tenor, with the rate, or methodology for this rate, and conventions for this rate (which will be compounded in arrears with a lookback and/or suspension period as a mechanism to determine the interest amount payable prior to the end of each interest period) being established by the calculation agent in accordance with:

(1) the rate, or methodology for this rate, and conventions for this rate selected or recommended by the Relevant Governmental Body for determining Compounded SOFR; provided that:

(2) if, and to the extent that, the calculation agent determines that Compounded SOFR cannot be determined in accordance with clause (1) above, then the rate, or methodology for this rate, and conventions for this rate that have been selected by the calculation agent giving due consideration to any industry-accepted market practice for U.S. dollar-denominated floating rate securities at such time.

For the avoidance of doubt, the calculation of Compounded SOFR shall exclude the Benchmark Replacement Adjustment and the spread of           basis points per annum.

“Interpolated Benchmark” with respect to the Benchmark means the rate determined by the calculation agent for the Corresponding Tenor by interpolating on a linear basis between: (i) the Benchmark for the longest period (for which the Benchmark is available) that is shorter than the Corresponding Tenor, and (ii) the Benchmark for the shortest period (for which the Benchmark is available) that is longer than the Corresponding Tenor.

“ISDA Definitions” means the 2006 ISDA Definitions published by the International Swaps and Derivatives Association, Inc. or any successor thereto, as amended or supplemented from time to time, or any successor definitional booklet for interest rate derivatives published from time to time.

“ISDA Fallback Adjustment” means the spread adjustment (which may be a positive or negative value or zero) that would apply for derivatives transactions referencing the ISDA Definitions to be determined upon the occurrence of an index cessation event with respect to the Benchmark for the applicable tenor.

“ISDA Fallback Rate” means the rate that would apply for derivatives transactions referencing the ISDA Definitions to be effective upon the occurrence of an index cessation date with respect to the Benchmark for the applicable tenor excluding the applicable ISDA Fallback Adjustment.

“Unadjusted Benchmark Replacement” means the Benchmark Replacement excluding the Benchmark Replacement Adjustment.

The terms “Reference Time,” “Relevant Governmental Body,” “SOFR” and “Term SOFR” have the meanings set forth above, under the heading “—Interest.”

Determinations and Decisions

We and the calculation agent are expressly authorized to make certain determinations, decisions, and elections under the terms of the Notes, including with respect to the use of Three-Month Term SOFR as the

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Benchmark for the floating rate period and under the benchmark transition provisions. Any determination, decision, or election that may be made by us or by the calculation agent under the terms of the Notes, including any determination with respect to the use of Three-Month Term SOFR as the Benchmark for the floating rate period, any determination under the benchmark transition provisions, any determination of a tenor, rate, or adjustment or of the occurrence or non-occurrence of an event, circumstance, or date and any decision to take or refrain from taking any action or any selection:

• will be conclusive and binding on the holders of the Notes and the Trustee absent manifest error;

• if made by us, will be made in our sole discretion;

• if made by the calculation agent, will be made after consultation with us, and the calculation agent will not make any such determination, decision or election to which we reasonably object; and

• notwithstanding anything to the contrary in the Indenture, shall become effective without consent from the holders of the Notes or the Trustee.

If the calculation agent fails to make any determination, decision or election that it is required to make under the terms of the Notes, then we will make that determination, decision or election on the same basis as described above. The Indenture provides that the Trustee will have no liability relating to any delay caused by the calculation agent’s failure to timely or appropriately determine the rate of interest borne by the Notes.

Calculation Agent

Wilmington Trust, National Association will initially act as calculation agent for the Notes.

Paying Agent

We may appoint one or more financial institutions to act as our paying agents, at whose designated offices the Notes in non-global form may be surrendered for payment at their maturity. We call each of those offices a paying agent. We may add, replace or terminate paying agents from time to time. We may also choose to act as our own paying agent. Initially, we have appointed the Trustee, at its principal corporate trust office at 1100 North Market Street, Rodney Square North, Wilmington, DE 19890, as the paying agent for the Notes. We must notify you of changes in the paying agents.

Governing Law

The Indenture provides that the Notes will be governed by, and construed in accordance with, the laws of the State of New York.

Tier 2 Capital

The Notes are intended to qualify as Tier 2 capital under the capital adequacy rules established by the Federal Reserve for bank holding companies, as the same may be amended or supplemented from time to time. The rules set forth specific criteria for instruments to qualify as Tier 2 capital. Among other things, the Notes must:

• be unsecured;

• have a minimum original maturity of at least five years;

• be subordinated to our depositors and general creditors;

• not contain provisions permitting the holders of the Notes to accelerate payment of principal prior to maturity except in the event of receivership, insolvency, liquidation or similar proceedings of a bank holding company or a major bank subsidiary;

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• only be callable after a minimum of five years following issuance, except upon the occurrence of a “Tax Event” or a “Tier 2 Capital Event” (as such terms are defined in the Indenture) or if we are required to register as an investment company pursuant to the Investment Company Act of 1940, as amended, and, in any case, subject to obtaining the prior approval of the Federal Reserve to the extent such approval is then required under the rules of the Federal Reserve; and

• unless the Federal Reserve authorizes us to do otherwise in writing, not be redeemed or repurchased unless they are replaced with an equivalent amount of other Tier 2 capital instruments or we can demonstrate to the satisfaction of the Federal Reserve that following redemption, we will continue to hold capital commensurate with our risk.

Clearance and Settlement

The Notes will be represented by one or more global certificates, which we refer to individually as a Global Note and collectively as the Global Notes, deposited with or on behalf of DTC and registered in the name of Cede & Co. or another nominee of DTC. The Notes will be available for purchase in minimum denominations of $1,000 and integral multiples of $1,000 in excess thereof in book-entry form only. So long as DTC or any successor depositary, which we refer to collectively as the “Depositary,” or its nominee is the registered owner of the Global Notes, the Depositary, or such nominee, as the case may be, will be considered to be the sole owner or holder of the Notes for all purposes of the Indenture. Beneficial interests in the Global Notes will be represented through book-entry accounts of financial institutions acting on behalf of beneficial owners as direct and indirect participants in DTC. Investors may not elect to receive a certificate representing their Notes while the Notes are held by a Depositary. Investors may elect to hold interests in the Global Notes through DTC either directly if they are participants in DTC or indirectly through organizations that are participants in DTC.

The laws of some jurisdictions may require that some purchasers of securities take physical delivery of securities in definitive form. These laws may impair the ability to transfer beneficial interests in the Notes, so long as the corresponding securities are represented by Global Notes.

DTC has advised us that it is a limited-purpose trust company organized under the New York Banking Law, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code and a “clearing agency” registered pursuant to the provisions of Section 17A of the Exchange Act. DTC holds securities that its direct participants deposit with DTC. DTC also facilitates the post-trade settlement among participants of sales and other securities transactions in deposited securities, through electronic computerized book-entry transfers and pledges between participants’ accounts. This eliminates the need for physical movement of securities certificates.

Direct participants include both U.S. and non-U.S. securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations. DTC is a wholly owned subsidiary of The Depository Trust & Clearing Corporation, which, in turn, is owned by a number of direct participants of DTC. Access to the DTC system is also available to others, referred to as indirect participants, such as both U.S. and non-U.S. securities brokers and dealers, banks, trust companies and clearing corporations that clear through or maintain a direct or indirect custodial relationship with a direct participant. The rules applicable to DTC and its participants are on file with the SEC.

Purchases of securities under the DTC system must be made by or through direct participants, which will receive a credit for the securities on DTC’s records. The ownership interest of each beneficial owner of securities will be recorded on the direct or indirect participants’ records. Beneficial owners will not receive written confirmation from DTC of their purchase. Beneficial owners are, however, expected to receive written confirmations providing details of the transaction, as well as periodic statements of their holdings, from the direct or indirect participant through which the beneficial owner entered into the transaction.

Under a book-entry format, holders may experience some delay in their receipt of payments, as such payments will be forwarded by the Depositary to Cede & Co., as nominee for DTC. DTC will forward the

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payments to its participants, who will then forward them to indirect participants or holders. Beneficial owners of securities other than DTC or its nominees will not be recognized by the relevant registrar, transfer agent, paying agent or trustee as registered holders of the securities entitled to the benefits of the Indenture. Beneficial owners that are not participants will be permitted to exercise their rights only indirectly through and according to the procedures of participants and, if applicable, indirect participants.

To facilitate subsequent transfers, all securities deposited by direct participants with DTC are registered in the name of DTC’s partnership nominee, Cede & Co., or such other name as may be requested by an authorized representative of DTC. The deposit of securities with DTC and their registration in the name of Cede & Co. or such other DTC nominee do not effect any change in beneficial ownership. DTC has no knowledge of the actual beneficial owners of the securities; DTC’s records reflect only the identity of the direct participants to whose accounts the securities are credited, which may or may not be the beneficial owners. The direct and indirect participants will remain responsible for keeping account of their holdings on behalf of their customers.

Conveyance of redemption notices and other communications by DTC to direct participants, by direct participants to indirect participants, and by direct and indirect participants to beneficial owners will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time. If less than all of the securities of any class are being redeemed, then DTC will determine the amount of the interest of each direct participant to be redeemed in accordance with its then current procedures.

Neither DTC nor Cede & Co. (nor any other DTC nominee) will consent or vote with respect to any securities unless authorized by a direct participant in accordance with DTC’s procedures. Under its usual procedures, DTC mails an omnibus proxy to the issuer as soon as possible after the record date. The omnibus proxy assigns Cede & Co.’s consenting or voting rights to those direct participants to whose accounts securities are credited on the record date (identified in a listing attached to the omnibus proxy).

DTC may discontinue providing its services as securities Depositary with respect to the Notes at any time by giving reasonable notice to the issuer or its agent. Under these circumstances, in the event that a successor securities Depositary is not obtained, certificates for the Notes are required to be printed and delivered. We may decide to discontinue the use of the system of book-entry-only transfers through DTC (or a successor securities Depositary). In that event, certificates for the Notes will be printed and delivered to DTC.

As long as DTC or its nominee is the registered owner of the Global Notes, DTC or its nominee, as the case may be, will be considered the sole owner and holder of the Global Notes and all securities represented by these certificates for all purposes under the instruments governing the rights and obligations of holders of such securities. Except in the limited circumstances referred to above, owners of beneficial interests in Global Notes:

• will not be entitled to have such global security certificates or the securities represented by these certificates registered in their names;

• will not receive or be entitled to receive physical delivery of securities certificates in exchange for beneficial interests in global security certificates; and

• will not be considered to be owners or holders of the global security certificates or any securities represented by these certificates for any purpose under the instruments governing the rights and obligations of holders of such securities.

All redemption proceeds, distributions and interest payments on the securities represented by the Global Notes and all transfers and deliveries of such securities will be made to DTC or its nominee, as the case may be, as the registered holder of the securities. DTC’s practice is to credit direct participants’ accounts upon DTC’s receipt of funds and corresponding detail information from the issuer or its agent, on the payable date in accordance with their respective holdings shown on DTC’s records. Payments by participants to beneficial owners will be governed by standing instructions and customary practices, as is the case with securities held for

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the accounts of customers in bearer form or registered in “street name,” and will be the responsibility of that participant and not of DTC, the Depositary, the issuer, the Trustee or any of their agents, subject to any statutory or regulatory requirements as may be in effect from time to time.

Payment of redemption proceeds, distributions and interest payments to Cede & Co. (or such other nominee as may be requested by an authorized representative of DTC) is the responsibility of the issuer or its agent, disbursement of such payments to direct participants will be the responsibility of DTC, and disbursement of such payments to the beneficial owners will be the responsibility of direct and indirect participants.

Ownership of beneficial interests in the Global Notes will be limited to participants or persons that may hold beneficial interests through institutions that have accounts with DTC or its nominee. Ownership of beneficial interests in Global Notes will be shown only on, and the transfer of those ownership interests will be effected only through, records maintained by DTC or its nominee, with respect to participants’ interests, or any participant, with respect to interests of persons held by the participant on their behalf. Payments, transfers, deliveries, exchanges, redemptions and other matters relating to beneficial interests in Global Notes may be subject to various policies and procedures adopted by DTC from time to time. None of Simmons, the Trustee or any agent for any of them will have any responsibility or liability for any aspect of DTC’s or any direct or indirect participant’s records relating to, or for payments made on account of, beneficial interests in Global Notes, or for maintaining, supervising or reviewing any of DTC’s records or any direct or indirect participant’s records relating to these beneficial ownership interests.

Although DTC has agreed to the foregoing procedures in order to facilitate transfer of interests in the Global Notes among participants, DTC is under no obligation to perform or continue to perform these procedures, and these procedures may be discontinued at any time. Neither Simmons nor the Trustee will have any responsibility for the performance by DTC or its direct participants or indirect participants under the rules and procedures governing DTC.

Because DTC can act only on behalf of direct participants, who in turn act only on behalf of direct or indirect participants, and certain banks, trust companies and other persons approved by it, the ability of a beneficial owner of securities to pledge them to persons or entities that do not participate in the DTC system may be limited due to the unavailability of physical certificates for the securities.

DTC has advised us that it will take any action permitted to be taken by a registered holder of any securities under the Indenture, only at the direction of one or more participants to whose accounts with DTC the relevant securities are credited.

The information in this section concerning DTC and its book-entry system has been obtained from sources that we believe to be accurate, but we assume no responsibility for the accuracy thereof.

Trustee

Wilmington Trust, National Association, will act as Trustee under the Indenture.

The Trustee may conclusively rely upon certificates, opinions or other documents furnished to it under the Indenture and shall have no responsibility to confirm or investigate the accuracy of mathematical calculations or other facts stated therein. The Trustee shall have no responsibility for monitoring Simmons’ compliance with any of its covenants under the Indenture.

Notices

Any notices required to be given to the holders of the Notes will also be given to the Trustee. Notwithstanding any other provision of the Indenture or any Note, where the Indenture or any Note provides for notice of any event or any other communication (including any notice of redemption or repurchase) to a holder of a Note (whether by mail or otherwise), such notice shall be sufficiently given if given to DTC (or its designee) pursuant to the applicable procedures of DTC or its designee, including by electronic mail in accordance with accepted practices at DTC.

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CERTAIN ERISA CONSIDERATIONS

The following is a summary of certain considerations associated with the purchase and holding of the Notes by (i) employee benefit plans subject to Title I of the U.S. Employee Retirement Income Security Act of 1974, as amended, which we refer to as “ERISA”, (ii) plans, individual retirement accounts and other arrangements subject to Section 4975 of the Internal Revenue Code of 1986, as amended, which we refer to as the “Code”, (iii) plans subject to any federal, state, local, non-U.S. or other laws or regulations that are similar to Title I of ERISA or Section 4975 of the Code, which we collectively refer to as “Similar Laws”, and (iv) entities whose underlying assets are considered to include “plan assets” of such employee benefit plans, plans or arrangements (each of which described in (i), (ii), (iii) and (iv) we call a “Plan”).

Each fiduciary of a Plan should consider the fiduciary standards of ERISA or any applicable Similar Laws in the context of the Plan’s particular circumstances before authorizing an investment in the Notes. Accordingly, among other factors, the fiduciary should consider whether the investment would satisfy the prudence and diversification requirements of ERISA or any applicable Similar Laws and would be consistent with the documents and instruments governing the Plan.

In addition, Section 406 of ERISA and Section 4975 of the Code prohibit Plans subject to Title I of ERISA or Section 4975 of the Code, which we call “ERISA Plans”, from engaging in certain transactions involving “plan assets” with persons that are “parties in interest” under ERISA or “disqualified persons” under Section 4975 of the Code with respect to the ERISA Plans. A violation of these “prohibited transaction” rules may result in an excise tax or other liabilities under ERISA and/or Section 4975 of the Code for those persons, unless exemptive relief is available under an applicable statutory or administrative exemption. In addition, the fiduciary of an ERISA Plan that engages in such a non-exempt prohibited transaction may be subject to penalties and liabilities under ERISA and/or the Code.

As a result of our business, we and certain of our affiliates may be considered parties in interest or disqualified persons with respect to many ERISA Plans. Prohibited transactions within the meaning of Section 406 of ERISA or Section 4975 of the Code could arise if the Notes were acquired by an ERISA Plan with respect to which we, any underwriter or any of our or their affiliates is a party in interest or a disqualified person. For example, if we are a party in interest or disqualified person with respect to an investing ERISA Plan (either directly or by reason of our ownership of our subsidiaries), the purchase of any Notes by an ERISA Plan could result in a sale or exchange that is prohibited by Section 406(a)(1)(A) of ERISA and Section 4975(c)(1)(A) of the Code or lending of money or other extension of credit that is prohibited by Section 406(a)(1)(B) of ERISA and Section 4975(c)(1)(B) of the Code, unless exemptive relief were available under an applicable exemption (see below).

The U.S. Department of Labor has issued prohibited transaction class exemptions, or PTCEs, that may provide exemptive relief for direct or indirect prohibited transactions resulting from the purchase, holding or disposition of the Notes. Those class exemptions include:

• PTCE 96-23 — for certain transactions determined by in-house asset managers;

• PTCE 95-60 — for certain transactions involving insurance company general accounts;

• PTCE 91-38 — for certain transactions involving bank collective investment funds;

• PTCE 90-1 — for certain transactions involving insurance company separate accounts; and

• PTCE 84-14 — for certain transactions determined by independent qualified professional asset managers.

In addition, ERISA Section 408(b)(17) and Section 4975(d)(20) of the Code provide an exemption for transactions between an ERISA Plan and a party in interest or disqualified person, provided that the party in

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interest or disqualified person is not a fiduciary (or an affiliate) who has or exercises any discretionary authority or control with respect to the investment of the ERISA Plan assets involved in the transaction or renders investment advice with respect to those assets, and is a party in interest or disqualified person solely by reason of being a service provider to the ERISA Plan or having a relationship to a service provider to the ERISA Plan and provided, further that the ERISA Plan pays no more than adequate consideration in connection with the transaction (the so-called “service provider exemption”). No assurance can be made that any such exemptions will be available, or that all of the conditions of any such exemptions will be satisfied, with respect to transactions involving the Notes.

Employee benefit plans that are governmental plans (as defined in Section 3(32) of ERISA), certain church plans (as defined in Section 3(33) of ERISA) and non-U.S. plans (as described in Section 4(b)(4) of ERISA) are not subject to the requirements of ERISA or Section 4975 of the Code, but may be subject to Similar Laws.

Because of the possibility that direct or indirect prohibited transactions or violations of Similar Laws could occur as a result of the purchase, holding or disposition of the Notes by a Plan, the Notes may not be purchased by any Plan, or any person investing the assets of any Plan, unless its purchase, holding and disposition of the Notes will not constitute or result in a non-exempt prohibited transaction under ERISA or Section 4975 of the Code or a violation of any Similar Laws.

Any purchaser or holder of the Notes or any interest in the Notes will be deemed to have represented by its purchase and holding of the Notes that either:

• it is not a Plan and is not purchasing the Notes or interest in the Notes on behalf of or with the assets of any Plan; or

• its purchase, holding and subsequent disposition of the Notes or interest in the Notes will not constitute or result in a non-exempt prohibited transaction under ERISA or the Code or a violation of any Similar Laws.

Due to the complexity of these rules and the penalties imposed upon persons involved in non-exempt prohibited transactions, it is important that any person considering the purchase of the Notes on behalf of or with the assets of any Plan consult with its counsel regarding the consequences under ERISA, the Code and any applicable Similar Laws of the acquisition, holding and disposition of the Notes, whether any exemption would be applicable, and whether all conditions of such exemption would be satisfied such that the acquisition and holding of the Notes by the Plan would be entitled to full exemptive relief thereunder.

Nothing herein shall be construed as, and the sale of the Notes to a Plan is in no respect, a representation or advice by us or the underwriters (or any of our or their affiliates) as to whether any investment in the Notes would meet any or all of the relevant legal requirements with respect to investment by, or is appropriate for, Plans generally or any particular Plan. The foregoing discussion is merely a summary and should not be construed as legal advice or as complete in all relevant respects.

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MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS

This section describes the material U.S. federal income tax considerations of the acquisition, ownership and disposition of the Notes we are offering. It is not a complete analysis of all the potential tax considerations relating to the Notes. This summary is based upon the provisions of the Code, Treasury Regulations promulgated under the Code, and currently effective administrative rulings and judicial decisions. These authorities may be changed, perhaps with retroactive effect, so as to result in U.S. federal income tax consequences different from those set forth below.

This summary is limited to beneficial owners (referred to in this summary as holders) of the Notes that purchase the Notes upon their initial issuance at their “issue price” (i.e., the first price at which a substantial amount of the Notes is sold for cash to investors (excluding sales to bond houses, brokers or similar persons or organizations acting in the capacity as underwriters, placement agents or wholesalers)) and that will hold the Notes as capital assets within the meaning of Section 1221 of the Code for U.S. federal income tax purposes. This summary does not address the tax considerations arising under the laws of any foreign, state or local jurisdiction. In addition, this discussion does not address any alternative minimum or Medicare contribution tax considerations, nor does it address all U.S. federal income tax considerations that may be applicable to holders’ particular circumstances or to holders that may be subject to special tax rules, such as, for example:

• banks, insurance companies, or other financial institutions;

• real estate investment trusts;

• regulated investment companies;

• controlled foreign corporations and their shareholders;

• passive foreign investment companies and their shareholders;

• tax-exempt organizations;

• qualified retirement plans, individual retirement accounts, and other deferred compensation arrangements;

• governmental entities;

• brokers and dealers in securities;

• certain U.S. expatriates;

• traders in securities that elect to use a mark-to-market method of accounting for their securities holdings;

• U.S. holders (as defined below) whose functional currency is not the U.S. dollar;

• holders subject to the special tax accounting rules under Section 451 of the Code;

• persons that will hold the Notes as a position in a hedging transaction, wash sale, straddle, conversion transaction, or other risk reduction or synthetic transaction; and

• entities or arrangements classified as partnerships or S corporations for U.S. federal income tax purposes or other pass-through entities or investors in such entities.

If an entity or arrangement classified as a partnership for U.S. federal income tax purposes holds the Notes, the tax treatment of a partner in the partnership will generally depend upon the status of the partner and the activities of the partnership. If you are an entity or arrangement classified as a partnership for U.S. federal income tax purposes that will hold Notes or a partner of such a partnership, you are urged to consult your tax advisor regarding the tax consequences of holding the Notes to you.

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This summary of material U.S. federal income tax considerations is for general information only and is not tax advice. You are urged to consult your tax advisor with respect to the application of U.S. federal income tax laws to your particular situation as well as any tax considerations arising under other U.S. federal tax laws (such as the estate or gift tax laws) or under the laws of any state, local, foreign or other taxing jurisdiction or under any applicable tax treaty.

U.S. Holders

This subsection describes the tax considerations for a “U.S. holder.” You are a “U.S. holder” if you are a beneficial owner of a Note and you are:

• an individual citizen or resident of the United States;

• a corporation (or other entity treated as a corporation for U.S. federal income tax purposes) created or organized in or under the laws of the United States, any state thereof, or the District of Columbia;

• an estate the income of which is subject to U.S. federal income tax regardless of its source; or

• a trust that (1) is subject to the supervision of a court within the United States if one or more “United States persons” (as defined in the Code) have the authority to control all substantial decisions of the trust, or (2) has a valid election in effect under applicable Treasury Regulations to be treated as a “United States person.”

Payments of interest and original issue discount.

Based on the interest rate characteristics of the Notes, we intend to treat the Notes as “variable rate debt instruments” (“VRDIs”) for U.S. federal income tax purposes and this discussion assumes such characterization to be correct.

Under applicable Treasury Regulations, to determine the amount of “qualified stated interest” (“QSI”) and original issue discount (“OID”) in respect of a variable rate debt instrument, an “equivalent fixed rate debt instrument” must be constructed. The equivalent fixed rate debt instrument of a variable rate debt instrument that has an initial fixed rate followed by one or more qualified floating rates, such as a Note, is constructed as follows: (i) first, the initial fixed rate is replaced with a qualified floating rate such that the fair market value of a Note as of the Note’s issue date would be approximately the same as the fair market value of an otherwise identical debt instrument that provides for the replacement qualified floating rate rather than the fixed rate, and (ii) second, each floating rate (including the floating rate determined under clause (i) of this paragraph) is converted into a fixed rate substitute (which, in each case, generally will be the value of each floating rate as of the issue date of the Notes).

When the equivalent fixed rate debt instrument has been constructed pursuant to the foregoing rules, the amount of QSI and OID, if any, are determined for the equivalent fixed rate debt instrument by applying the general OID rules to the equivalent fixed rate debt instrument, and a U.S. holder of the Notes will account for such OID, if any, and QSI as if the U.S. holder held the equivalent fixed rate debt instrument. For each accrual period, appropriate adjustments will be made to the amount of QSI or OID assumed to have been accrued or paid with respect to the equivalent fixed rate debt instrument in the event that such amounts differ from the actual amount of interest accrued or paid on the Notes during the accrual period.

The applicable Treasury Regulations provide special rules for determining the yield and maturity of a debt instrument, such as the Notes, that provide an issuer with the option to redeem the instrument at specified times. The Treasury Regulations generally deem an issuer to exercise a redemption option in a manner that minimizes the yield on the debt instrument for purposes of determining whether a debt instrument is issued with OID. Under the terms of the Notes, if the initial fixed rate substitute on the equivalent fixed rate debt instrument (as determined in the manner described above) is less than the fixed rate substitute of the floating rate (as determined

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in the manner described above), the yield on the Notes will be minimized if the Notes are redeemed immediately before the change in the interest rate on    , 2030, and, therefore, the Notes will be treated as maturing on such date for OID purposes. This assumption is made solely for purposes of determining whether the Notes are issued with OID for U.S. federal income tax purposes and is not an indication of our intention to redeem or not to redeem the Notes at any time. If, contrary to this presumption, the Notes are not redeemed prior to the change in the interest rate on    , 2030, then, solely for OID purposes, the Notes will be deemed to be reissued at their adjusted issue price on the date that they are not redeemed. This deemed reissuance should not result in taxable gain or loss to U.S. holders.

It is anticipated that based on current market conditions and the manner in which the interest rates on the Notes are determined, and this discussion assumes, that the Notes will be issued without original issue discount for U.S. federal income tax purposes. In such case, interest on a Note will be includible by a U.S. holder as interest income at the time it accrues or is received in accordance with its method of accounting for U.S. federal income tax purposes and will be ordinary income.

Sale, exchange, retirement or other taxable disposition. Upon the sale, exchange, retirement or other taxable disposition of a Note, a U.S. holder will recognize taxable gain or loss equal to the difference between the amount realized on such disposition (except to the extent any amount realized is attributable to accrued but unpaid interest, which will be treated as a payment of interest) and the U.S. holder’s adjusted tax basis in the Note. A U.S. holder’s adjusted tax basis in a Note generally will be its cost. Gain or loss recognized on the disposition of a Note generally will be capital gain or loss, and will be long-term capital gain or loss if, at the time of the disposition, the U.S. holder’s holding period for the Note is more than one year. Long-term capital gains of non-corporate taxpayers are generally eligible for preferential rates of taxation. The deductibility of capital losses is subject to certain limitations.

Information reporting and backup withholding. Information returns are required to be filed with the IRS in connection with payments on the Notes and proceeds received from a sale or other disposition of the Notes unless the U.S. holder is an exempt recipient. A U.S. holder may also be subject to backup withholding on these payments in respect of the U.S. holder’s Notes unless the U.S. holder provides a taxpayer identification number and otherwise complies with applicable requirements of the backup withholding rules or the U.S. holder provides proof of an applicable exemption. Amounts withheld under the backup withholding rules are not additional taxes and may be refunded or credited against the U.S. holder’s U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

Non-U.S. Holders

This subsection describes the tax considerations for a “non-U.S. holder.” You are a “non-U.S. holder” if you are the beneficial owner of a Note that is neither a U.S. holder nor an entity or arrangement classified as a partnership for U.S. federal income tax purposes.

Payments of interest. Subject to the discussion under “— Information reporting and backup withholding” and “— FATCA” below, payments of principal and interest on the Notes to a non-U.S. holder generally will be exempt from U.S. federal income or withholding tax if, in the case of the payments of interest:

• the non-U.S. holder does not own, actually or constructively, 10% or more of the combined voting power of all classes of our stock entitled to vote;

• the non-U.S. holder is not a “controlled foreign corporation” for U.S. federal income tax purposes that is related to us through stock ownership;

• the non-U.S. holder certifies under penalties of perjury on IRS Form W-8BEN or, if applicable, W-8BEN-E that the non-U.S. holder is not a United States person; and

• the non-U.S. holder is not receiving such interest as income effectively connected with the conduct by the non-U.S. holder of a trade or business within the United States.

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If a non-U.S. holder cannot satisfy one of the first three requirements described above and interest on the Notes is not exempt from withholding because it is effectively connected with the non-U.S. holder’s conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, is attributable to the non-U.S. holder’s U.S. permanent establishment or fixed base), as described below, payments of interest on the Notes will be subject to withholding tax at a rate of 30%, or the rate specified by an applicable treaty.

Sale, exchange or other taxable disposition. A non-U.S. holder generally will not be subject to U.S. federal income or withholding tax on gain realized on a sale, redemption or other taxable disposition of Notes, unless the gain is effectively connected with the non-U.S. holder’s conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, is attributable to the non-U.S. holder’s U.S. permanent establishment or fixed base), as described below. However, any proceeds attributable to accrued interest will be treated as described in “— Payments of interest” above.

Income or gain effectively connected with a U.S. trade or business. If interest or gain on the Notes is effectively connected with a non-U.S. holder’s conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, is attributable to a U.S. permanent establishment or fixed base maintained by a non-U.S. holder), a non-U.S. holder will generally be taxed in the same manner as a U.S. holder. In this case, a non-U.S. holder will be exempt from the withholding tax on interest discussed above, although a non-U.S. holder will be required to provide a properly executed IRS Form W-8ECI in order to claim an exemption from withholding.

Non-U.S. holders should consult their tax advisors with respect to other U.S. tax consequences of the ownership and disposition of Notes, including the possible imposition of a branch profits tax at a rate of 30% (or a lower treaty rate) if the non-U.S. holder is a corporation.

Information reporting and backup withholding. Information returns are required to be filed with the IRS in connection with payments of interest on the Notes. Unless the non-U.S. holder complies with certification procedures to establish that the non-U.S. holder is not a United States person, information returns may also be filed with the IRS in connection with the proceeds from a sale or other disposition of a note. A non-U.S. holder may be subject to backup withholding on payments on the Notes or on the proceeds from a sale or other disposition of the Notes unless the non-U.S. holder complies with certification procedures to establish that a non-U.S. holder is not a United States person or otherwise establish an exemption. The certification procedures required to claim the exemption from withholding tax on interest described above will satisfy the certification requirements necessary to avoid backup withholding as well.

Amounts withheld under the backup withholding rules are not additional taxes and may be refunded or credited against the non-U.S. holder’s U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

FATCA. Provisions commonly referred to as “FATCA” impose withholding of 30% on payments of interest on the Notes and on payments of gross proceeds of sales or redemptions of the Notes to “foreign financial institutions” (which is broadly defined for this purpose and in general includes investment vehicles and financial intermediaries) and certain other non-U.S. entities unless various U.S. information reporting and due diligence requirements (generally relating to ownership by U.S. persons of interests in or accounts with those entities) have been satisfied, or an exemption applies. However, proposed Treasury Regulations (the preamble to which specifies that taxpayers are permitted to rely on them pending finalization) eliminate the withholding requirement on payments of gross proceeds of a taxable disposition (other than any amount treated as interest). Holders are encouraged to consult with their own tax advisors regarding the possible implications of FATCA on their investment in the Notes.

The discussion of U.S. federal income tax considerations set forth above is included for general information only and may not be applicable depending upon a holder’s particular situation. Prospective

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purchasers of the Notes are urged to consult their own tax advisors with respect to the tax consequences to them of the purchase, ownership and disposition of Notes, including the tax consequences under state, local, estate, foreign and other tax laws and the possible effects of changes in U.S. or other tax laws.

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UNDERWRITING

We have entered into an underwriting agreement, dated    , 2025, with Keefe, Bruyette & Woods, Inc. and Morgan Stanley & Co. LLC, as representatives of the underwriters named below. Subject to certain conditions, each underwriter has agreed, severally but not jointly, to purchase the aggregate principal amount of Notes in this offering set forth next to its name in the following table.

Underwriters		Principal Amount of Notes
Keefe, Bruyette & Woods, Inc.
Morgan Stanley & Co. LLC
Total:

The underwriting agreement provides that the obligations of the several underwriters to purchase the Notes offered hereby are subject to certain conditions precedent and that the underwriters are obligated to purchase all of the Notes offered by this prospectus supplement if any of the Notes are purchased.

We have agreed to indemnify the underwriters against some specified types of liabilities, including liabilities under the Securities Act of 1933, as amended, and to contribute to payments the underwriters may be required to make in respect of any of these liabilities.

The Notes sold by the underwriters to the public will be offered at the public offering price set forth on the cover of this prospectus supplement. The underwriters may offer the Notes to selected dealers at the public offering price set forth on the cover of this prospectus supplement less a concession not in excess of         % of the principal amount per note. After the initial offering, the underwriters may change the offering price and the other selling terms. The offering of the Notes by the underwriters is subject to receipt and acceptance and subject to the underwriters’ right to reject any order in whole or in part.

Underwriting Discounts, Commissions and Expenses

The following table shows the public offering price, the underwriting discounts and commissions that we are to pay the underwriters and the proceeds, before expenses, to us in connection with this offering (expressed as a percentage of the principal amount of the Notes offered hereby).

		Per Note				Total
Public Offering Price(1)		$				$
Underwriting discounts and commissions		$				$
Proceeds to us (before expenses)		$				$

(1) Plus accrued interest from     , 2025, to the date of delivery.

We estimate expenses payable by us in connection with this offering, other than, in each case, underwriting discounts and commissions, will be approximately $     . This estimate reflects that we may reimburse the underwriters for certain of their reasonable out-of-pocket expenses incurred in connection with their engagement as underwriters, including certain expenses attributable to legal fees and marketing, syndication and travel. The underwriters may also reimburse us for certain of our expenses related to the offering.

Indemnity

We have agreed to indemnify the underwriters and their affiliates, selling agents and controlling persons against certain liabilities, including certain liabilities under the Securities Act. If we are unable to provide this indemnification, we will contribute to the payments the underwriters and their affiliates, selling agents and controlling persons may be required to make in respect of those liabilities.

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No Public Trading Market

There is currently no public trading market for the Notes. In addition, we have not applied and do not intend to apply to list the Notes on any national securities exchange or to have the Notes quoted on an automated dealer quotation system. The underwriters have advised us that they intend to make a market in the Notes. However, the underwriters are not obligated to do so and may discontinue any market-making in the Notes at any time in their sole discretion and without prior notice. Therefore, we cannot assure you that a liquid trading market for the Notes will develop or continue, that you will be able to sell your Notes at a particular time, or that the price that you receive when you sell will be favorable.

No Sale of Similar Securities

We have agreed with the underwriters that for a period from the date of the Underwriting Agreement through and including the closing date of the offering, we and our subsidiaries will not, without the prior consent of the underwriters, offer or sell, or enter into any agreement to sell, any debt securities (excluding deposit obligations) of ours or of our subsidiaries.

Stabilization Transactions

In connection with this offering of the Notes, the underwriters may engage in overallotment, stabilizing transactions and syndicate covering transactions. Overallotment involves sales of Notes in excess of the offering size, which may create a short position for the underwriters. Stabilizing transactions involve bids to purchase the Notes in the open market for the purpose of pegging, fixing or maintaining the price of the Notes. Syndicate covering transactions involve purchases of the Notes in the open market after the distribution has been completed in order to cover short positions. The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the other underwriters a portion of the underwriting discount received by it because the representative has repurchased Notes sold by or for the account of such underwriter in stabilizing or syndicate covering transactions. Stabilizing transactions and syndicate covering transactions, and together with the imposition of a penalty bid, may cause the price of the Notes to be higher than it would otherwise be in the absence of those transactions. If the underwriters engage in stabilizing or syndicate covering transactions, they may discontinue them at any time without notice.

Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the Notes. In addition, neither we nor any of the underwriters make any representation that the underwriters will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice

Electronic Prospectus Delivery

This prospectus supplement and the accompanying prospectus may be made available in electronic format on websites or through other online services maintained by the underwriters or their affiliates.

Other than the prospectus supplement and the accompanying prospectus in electronic format, information on such websites and any information contained in any other website maintained by any of the underwriters or their affiliates is not part of this prospectus supplement or our registration statement of which the related prospectus forms a part, has not been approved or endorsed by us or the underwriters in their capacity as underwriters and should not be relied on by investors.

Other Activities and Relationships

The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory,

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investment management, investment research, principal investment, hedging, financing and brokerage activities. Certain of the underwriters and their respective affiliates have, from time to time, performed, and may in the future perform, various commercial and investment banking and financial advisory services for us and our affiliates, for which they received or will receive customary fees and expenses.

Morgan Stanley, one of the joint book-running managers in this offering, provided advisory and execution services in connection with our balance sheet repositioning transaction completed on July 23, 2025.

In addition, in the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers, and such investment and securities activities may involve securities or instruments issued by us and our affiliates. If the underwriters or their respective affiliates have a lending relationship with us, they routinely hedge their credit exposure to us consistent with their customary risk management policies. The underwriters and their respective affiliates may hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities or the securities of our affiliates. Any such short positions could adversely affect future trading prices of the securities offered hereby. The underwriters and their respective affiliates may also communicate independent investment recommendations, market color or trading ideas or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long or short positions in such securities and instruments.

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LEGAL MATTERS

The validity of the securities offered hereby and certain other legal matters in connection with the offering will be passed upon for us by Troutman Pepper Locke LLP. Nelson Mullins Riley  & Scarborough, LLP will pass upon certain legal matters for the underwriters.

EXPERTS

The consolidated financial statements of Simmons First National Corporation as of December 31, 2024 and 2023 and for each of the years in the three-year period ended December 31, 2024 and the effectiveness of internal control over financial reporting as of December 31, 2024 incorporated in this prospectus supplement by reference from the Annual Report have been audited by Forvis Mazars, LLP, an independent registered public accounting firm, as stated in their reports thereon, incorporated herein by reference, and have been incorporated in this prospectus supplement in reliance upon such reports and upon the authority of such firm as experts in accounting and auditing.

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PROSPECTUS

Class A Common Stock

Preferred Stock

Debt Securities

Depositary Shares

Warrants

Purchase Contracts

Subscription Rights

Units

We may offer and sell from time to time, together or separately, in one or more offerings, any combination of the securities listed above. The securities we may offer may be convertible into or exchangeable for other securities. The securities listed above may be offered by us and/or may be offered and sold, from time to time, by one or more selling shareholders to be identified in the future. Each time we offer any securities pursuant to this prospectus, we will provide you with a prospectus supplement that will describe the specific amounts, prices and terms of the securities being offered. You should read this prospectus, the information incorporated by reference in this prospectus, the accompanying prospectus supplement, including any information incorporated by reference therein, and any free writing prospectus carefully before you invest in the securities described in the applicable prospectus supplement.

Our common stock is listed on the Nasdaq Global Select Market and trades under the ticker symbol “SFNC.”

We may offer and sell these securities to or through one or more underwriters, dealers and agents, directly to purchasers or through a combination of these methods, on a continuous or delayed basis from time to time. The names of any underwriters, dealers or agents involved in the distribution of our securities, their compensation and any option they hold to acquire additional securities will be described in the applicable prospectus supplement. Net proceeds from the sale of securities will be set forth in the applicable prospectus supplement.

This prospectus may not be used to sell securities unless accompanied by the applicable prospectus supplement.

Investing in our securities involves certain risks. See “Risk Factors” beginning on page 4 of this prospectus and contained in our Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated herein by reference, as well as any risk factors included in, or incorporated by reference into, the applicable prospectus supplement, to read about factors you should consider before buying any securities issued by us.

These securities are not savings accounts, deposits or other obligations of any of our bank and non-bank subsidiaries and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Neither the U.S. Securities and Exchange Commission, any state securities commission, the Federal Deposit Insurance Corporation, the Board of Governors of the Federal Reserve System nor any other regulatory body has approved or disapproved of these securities or determined if this prospectus is accurate or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is May 17, 2024.

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		Page
About This Prospectus			1
Where You Can Find More Information			2
The Company			3
Risk Factors			4
Use of Proceeds			4
Legal Matters			4
Experts			4

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ABOUT THIS PROSPECTUS

This prospectus is part of an automatic shelf registration statement that we filed with the U.S. Securities and Exchange Commission, or the SEC, as a “well-known seasoned issuer,” as defined under Rule 405 under the Securities Act of 1933, as amended, or the Securities Act. Under this shelf registration statement, we may offer and sell from time to time any combination of our Class A common stock, which we refer to as our common stock, preferred stock, senior debt securities, subordinated debt securities, depositary shares, warrants, purchase contracts, subscription rights and units in one or more offerings up to an indeterminate total dollar amount. The preferred stock, debt securities, warrants, purchase contracts, subscription rights and units may be convertible into or exercisable or exchangeable for common or preferred stock or other securities issued by us or debt or equity securities issued by one or more other entities.

Each time we offer and sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read this prospectus and the applicable prospectus supplement together with the additional information described under the heading “Where You Can Find More Information.” We may also prepare free writing prospectuses that describe particular securities. Any free writing prospectus should also be read in connection with this prospectus and with any prospectus supplement referred to therein. For purposes of this prospectus, any reference to an applicable prospectus supplement may also refer to a free writing prospectus, unless the context otherwise requires. Unless otherwise indicated or the context otherwise requires, all references in this prospectus to “we,” “our,” “us,” “ourselves,” and “the Company” refer to Simmons First National Corporation, an Arkansas corporation, and its consolidated subsidiaries.

The registration statement that contains this prospectus, including the exhibits to the registration statement, contains additional information about us and the securities offered under this prospectus. The registration statement can be read at the SEC website mentioned under the heading “Where You Can Find More Information.”

The distribution of this prospectus and any applicable prospectus supplement and the offering of the securities in certain jurisdictions may be restricted by law. Persons into whose possession this prospectus and any applicable prospectus supplement come should inform themselves about and observe any such restrictions. This prospectus and any applicable prospectus supplement do not constitute, and may not be used in connection with, an offer or solicitation by anyone in any jurisdiction in which such offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to any person to whom it is unlawful to make such offer or solicitation.

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WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public at the SEC’s website at www.sec.gov.

The SEC allows us to “incorporate by reference” into this prospectus the information in documents we file with the SEC, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus and should be read with the same care. When we update the information contained in documents that have been incorporated by reference, by making future filings with the SEC, the information incorporated by reference in this prospectus is considered to be automatically updated and superseded. In other words, in all cases, if you are considering whether to rely on information contained in this prospectus or information incorporated by reference into this prospectus, you should rely on the information contained in the document that was filed later. We incorporate by reference the documents listed below (File No. 000-06253), which are considered to be a part of this prospectus:

• our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 27, 2024;

• our Quarterly Report on Form 10-Q for the quarter ended March 31, 2024, filed with the SEC on May 7, 2024;

• the information in our Definitive Proxy Statement on Schedule 14A for our 2024 Annual Meeting of Shareholders, filed with the SEC on March  20, 2024, to the extent incorporated by reference in Part III of our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 27, 2024;

• our Current Reports on Form 8-K filed on January 3, 2024, January  8, 2024, January  24, 2024 (only with respect to Item 8.01 thereof), January  26, 2024, March  1, 2024, March  14, 2024 and April 26, 2024; and

• the description of our capital stock set forth in Exhibit 4.2 to our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on February 27, 2023, including any amendment or report filed for the purpose of updating such description.

All reports and other documents we subsequently file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, or the Exchange Act, until our offering is completed will also be incorporated by reference into this prospectus and deemed to be part hereof (other than any information furnished to, rather than filed with, the SEC, unless expressly stated otherwise therein). The most recent information that we file with the SEC automatically updates and supersedes older information.

Any documents incorporated by reference into this prospectus are available without charge to you on the Internet at www.simmonsbank.com or by contacting our Investor Relations officer at Simmons First National Corporation, P.O. Box 7009, Pine Bluff, Arkansas 71611, Attention: Ed Bilek, (870) 541-1000. The reference to our website is not intended to be an active link and the information on our website is not, and you must not consider the information to be, a part of this prospectus.

You should rely only on the information contained or incorporated by reference in this prospectus and the applicable prospectus supplement. Neither we nor any underwriter or agent have authorized anyone else to provide you with additional or different information. We may only use this prospectus to sell securities if it is accompanied by a prospectus supplement. We are only offering these securities in jurisdictions where the offer is permitted. You should not assume that the information in this prospectus or the applicable prospectus supplement or any document incorporated by reference is accurate as of any date other than the dates of the applicable documents.

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THE COMPANY

Simmons First National Corporation, an Arkansas corporation organized in 1968, is a financial holding company registered under the Bank Holding Company Act of 1956, as amended. We are headquartered in Pine Bluff, Arkansas, and had total consolidated assets of $27.4 billion, total consolidated loans of $17.0 billion, total consolidated deposits of $22.4 billion and equity capital of $3.4 billion, each as of March 31, 2024. Through our subsidiaries, we provide banking and other financial products and services in markets located in Arkansas, Kansas, Missouri, Oklahoma, Tennessee and Texas.

We seek to build shareholder value by, among other things, focusing on strong asset quality, maintaining strong capital, managing our liquidity position, improving our operational efficiency and opportunistically growing our business, both organically and through mergers with and acquisitions of other financial institutions. Our business philosophy centers on building strong, deep customer relationships through excellent customer service and integrity in our operations. While we have grown in recent years into a regional financial institution and one of the largest bank/financial holding companies headquartered in the State of Arkansas, we continue to emphasize, where practicable, a community-based mindset focused on local associates responding to local banking needs and making business decisions in the markets they serve. Those efforts, though, are buttressed by experienced, centralized support functions in select, critical areas.

Our common stock is traded on the Nasdaq Global Select Market under the symbol “SFNC.” Our principal executive offices are located at 501 Main Street, Pine Bluff, Arkansas 71601, and our telephone number is (870) 541-1000. We also have corporate offices in Little Rock, Arkansas.

Additional information about us and our subsidiaries is included in documents incorporated by reference in this prospectus. See “Where You Can Find More Information.”

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RISK FACTORS

Investing in securities issued by us involves certain risks. Before you invest in any securities issued by us, in addition to the other information included in, or incorporated by reference into, this prospectus, you should carefully consider the risk factors contained in Part I, Item 1A under the caption “Risk Factors” and elsewhere in our Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated by reference into this prospectus, as updated by our annual or quarterly reports for subsequent fiscal years or fiscal quarters that we file with the SEC and that are so incorporated. See “Where You Can Find More Information” for information about how to obtain a copy of these documents. You should also carefully consider the risks and other information that may be contained in, or incorporated by reference into, any prospectus supplement relating to specific offerings of securities.

USE OF PROCEEDS

We intend to use the net proceeds from the sales of the securities in the manner and for the purposes set forth in the applicable prospectus supplement, which may include general corporate purposes.

LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, the validity of the securities will be passed upon for us by Friday, Eldredge & Clark LLP, Little Rock, Arkansas and Covington & Burling LLP, New York, New York. Friday, Eldredge & Clark LLP and Covington & Burling LLP regularly perform legal services for us. Certain legal matters will be passed upon for any underwriters, dealers or agents by the counsel to such underwriters specified in the applicable prospectus supplement.

EXPERTS

The audited annual consolidated financial statements of the Company appearing in our Annual Report on Form 10-K for the year ended December 31, 2023 and the effectiveness of our internal control over financial reporting as of such date have been audited by FORVIS, LLP, an independent registered public accounting firm, as set forth in its reports included therein, which are incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in auditing and accounting.

With respect to the unaudited interim consolidated financial information of the Company appearing in our Quarterly Report on Form 10-Q for the period ended March 31, 2024, which is incorporated herein by reference, FORVIS, LLP has applied limited procedures in accordance with professional standards for review of such information. However, as stated in its separate report included therein, FORVIS, LLP did not audit and it does not express an opinion on that interim financial information. Because of the limited nature of the review procedures applied, the degree of reliance on its reports on such information should be restricted. Pursuant to Rule 436(c) under the Securities Act, this report on the Company’s unaudited interim consolidated financial information should not be considered a part of the registration statement prepared or certified by its independent registered public accounting firm within the meaning of Sections 7 and 11 of the Securities Act.

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Simmons First National Corporation

% Fixed-to-Floating Subordinated Notes due 2035

Prospectus Supplement

September  , 2025

Joint Book-Running Managers

Keefe, Bruyette & Woods		Morgan Stanley
A Stifel Company

FAQ

What are the Notes being offered by Simmons First National Corporation (SFNC)?

The offering is fixed-to-floating rate subordinated notes due 2035, with the floating rate expected to be Three-Month Term SOFR plus a spread; interest calculation conventions are described in the prospectus supplement.

How will Simmons use the proceeds from the offering?

Proceeds, together with cash on hand if needed, are intended to repay in full the $330 million principal amount of the 2028 Notes on October 1, 2025 and for general corporate purposes.

What is Simmons’ consolidated liability position as of June 30, 2025?

As of June 30, 2025, consolidated total liabilities were approximately $23.1 billion, including about $21.8 billion of deposit liabilities.

Are the Notes secured or subordinated?

The Notes are subordinated; they rank equally with certain subordinated debentures and are junior to Senior Indebtedness.

Was any portion of existing subordinated debt recently redeemed?

Yes; $37.0 million related to the Spirit Notes was redeemed in full on July 31, 2025.

Does the Indenture limit Simmons from incurring more debt?

No; the Indenture governing the Notes does not limit the amount of additional indebtedness the company or its subsidiaries may incur.