Southern Co (SO) prices $1.3B 6.00% junior subordinated notes due 2058

Rhea-AI Filing Summary

The Southern Company agreed to issue and sell $1,300,000,000 of Series 2026A 6.00% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due April 1, 2058. The company entered into an Underwriting Agreement with a syndicate led by Citigroup, J.P. Morgan, Mizuho, Morgan Stanley and U.S. Bancorp.

The new junior subordinated notes are registered under an existing shelf registration statement and are governed by a Seventeenth Supplemental Indenture. Legal and tax opinions, as well as the form of note and related consents, are filed as exhibits.

Insights

Capital structure and credit analyst

Southern adds $1.3B in long-dated junior subordinated debt.

The Southern Company is issuing $1,300,000,000 of Series 2026A 6.00% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2058. These are deeply long-dated, junior instruments that typically sit below senior debt in the capital structure.

The notes are issued under an existing shelf registration and a Seventeenth Supplemental Indenture, with a defined reset-rate structure. Legal and tax opinions from Troutman Pepper Locke LLP support the issuance, indicating a standard, structured capital markets transaction rather than an operational shift.

The scale and subordinated nature of this debt affect leverage mix and hybrid-equity treatment, but the net impact depends on how the proceeds are ultimately deployed. Future periodic reports and financial statements will clarify how this new layer of capital interacts with existing obligations.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D. C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) March 16, 2026

Commission
File Number Registrant,
State of Incorporation,
Address and Telephone Number I.R.S. Employer
Identification No.

1-3526 The Southern Company 58-0690070

(A Delaware Corporation)

30 Ivan Allen Jr. Boulevard, N.W.

Atlanta, Georgia 30308

(404) 506-5000

The name and address of the registrant have not changed since the last report.

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Registrant			Title of each class			Trading Symbol(s)			Name of each exchange on which registered
The Southern Company			Common Stock, par value $5 per share			SO			New York Stock Exchange
The Southern Company			Series 2017B 5.25% Junior Subordinated Notes due 2077			SOJC			New York Stock Exchange
The Southern Company			Series 2020A 4.95% Junior Subordinated Notes due 2080			SOJD			New York Stock Exchange
The Southern Company			Series 2020C 4.20% Junior Subordinated Notes due 2060			SOJE			New York Stock Exchange
The Southern Company			Series 2021B 1.875% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2081			SO 81			New York Stock Exchange
The Southern Company			Series 2025A 6.50% Junior Subordinated Notes due 2085			SOJF			New York Stock Exchange
The Southern Company			2025 Series A Corporate Units			SOMN			New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Item 8.01. Other Events.

On March 16, 2026, The Southern Company (the “Company”) entered into an Underwriting Agreement with Citigroup Global Markets Inc., J.P. Morgan Securities LLC, Mizuho Securities USA LLC, Morgan Stanley & Co. LLC and U.S. Bancorp Investments, Inc., as representatives of the several Underwriters named in Schedule I thereto (the “Underwriters”), covering the issue and sale of $1,300,000,000 aggregate principal amount of its Series 2026A 6.00% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due April 1, 2058 (the “Series 2026A Junior Subordinated Notes”). The Series 2026A Junior Subordinated Notes were registered under the Securities Act of 1933, as amended, pursuant to the shelf registration statement (Registration No. 333-277138) of the Company.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.
1.3			Underwriting Agreement relating to the Series 2026A Junior Subordinated Notes, dated March 16, 2026, among the Company and Citigroup Global Markets Inc., J.P. Morgan Securities LLC, Mizuho Securities USA LLC, Morgan Stanley & Co. LLC and U.S. Bancorp Investments, Inc., as representatives of the several Underwriters named in Schedule I thereto.
4.4			Seventeenth Supplemental Indenture to Subordinated Note Indenture dated as of March 19, 2026, providing for the issuance of the Series 2026A Junior Subordinated Notes.
4.8			Form of the Series 2026A Junior Subordinated Note (included in Exhibit 4.4 above).
5.1			Opinion of Troutman Pepper Locke LLP relating to the Series 2026A Junior Subordinated Notes.
8.1			Tax Opinion of Troutman Pepper Locke LLP relating to the Series 2026A Junior Subordinated Notes.
23.1			Consent of Troutman Pepper Locke LLP (included in Exhibit 5.1 above).
23.2			Consent of Troutman Pepper Locke LLP (included in Exhibit 8.1 above).
104			Cover Page Interactive Data File – The cover page iXBRL tags are embedded within the inline XBRL document.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date:   March 19, 2026			THE SOUTHERN COMPANY
			By			/s/Melissa K. Caen
						Melissa K. Caen Assistant Secretary

2

FAQ

What did The Southern Company (SO) announce in this 8-K?

The Southern Company agreed to issue and sell $1.3 billion of Series 2026A 6.00% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due April 1, 2058. The transaction is documented through an Underwriting Agreement with a syndicate of major investment banks.

What are the key terms of Southern Company’s Series 2026A junior subordinated notes?

The Series 2026A Junior Subordinated Notes carry a 6.00% Fixed-to-Fixed Reset Rate coupon and mature on April 1, 2058. The total aggregate principal amount is $1,300,000,000, and the notes are junior subordinated obligations under a Seventeenth Supplemental Indenture.

Which banks are underwriting The Southern Company’s new $1.3 billion notes?

Citigroup Global Markets, J.P. Morgan Securities, Mizuho Securities USA, Morgan Stanley & Co., and U.S. Bancorp Investments act as representatives of the underwriters. They are party to the Underwriting Agreement covering the issue and sale of the Series 2026A Junior Subordinated Notes.

Under what registration is Southern Company’s 2026A junior subordinated debt issued?

The Series 2026A Junior Subordinated Notes are registered under The Southern Company’s shelf registration statement with Registration No. 333-277138. This allows the company to issue these securities to the market under previously cleared offering documentation.

What exhibits accompany The Southern Company’s 8-K about the 2026A notes?

Exhibits include the Underwriting Agreement, the Seventeenth Supplemental Indenture, the form of the Series 2026A note, legal and tax opinions from Troutman Pepper Locke LLP, and related consents, plus the cover page interactive data file with inline XBRL tags embedded.

When did The Southern Company approve the 2026A junior subordinated notes deal?

The Southern Company entered into the Underwriting Agreement on March 16, 2026, and the related Seventeenth Supplemental Indenture providing for issuance of the Series 2026A Junior Subordinated Notes is dated March 19, 2026, aligning with the signing of the 8-K.

Filing Exhibits & Attachments

8 documents

Other Documents

• EX-1.3 EX-1.3 208.1 KB
• EX-4.4 EX-4.4 149.4 KB
• EX-5.1 EX-5.1 17.0 KB
• EX-8.1 EX-8.1 11.6 KB
• EX-101 XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT 4.1 KB
• EX-101 XBRL TAXONOMY EXTENSION DEFINITION LINKBASE DOCUMENT 17.8 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT 34.6 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT 18.8 KB