Auditor switch at LanzaTech (NASDAQ: LNZA) after going concern note

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

8-K/A

Rhea-AI Filing Summary

LanzaTech Global, Inc. filed an amended report to add a letter from Deloitte & Touche LLP confirming it agrees with the company’s description of their auditor change. On April 10, 2026, LanzaTech’s board dismissed Deloitte as independent auditor and approved the appointment of BDO USA, P.C. for the 2026 fiscal year.

Deloitte’s audit reports for 2024 and 2025 were clean except for an explanatory paragraph citing substantial doubt about LanzaTech’s ability to continue as a going concern. The company also disclosed material weaknesses in internal control over financial reporting in both years, spanning complex transactions, revenue recognition, and several core internal control components. These weaknesses did not lead to restated financial statements, and the company reports no disagreements or additional reportable events with Deloitte. Deloitte has been authorized to fully brief BDO on these issues.

Positive

None.

Negative

Deloitte’s audit reports for 2024 and 2025 included an explanatory paragraph expressing substantial doubt about LanzaTech’s ability to continue as a going concern.
LanzaTech reported recurring material weaknesses in internal control over financial reporting in 2024 and 2025, including issues with complex transactions, revenue recognition, and several key internal control components.

Insights

Auditor change combines with going concern and control weaknesses, raising risk.

LanzaTech Global, Inc. replaced Deloitte with BDO as independent auditor effective April 10, 2026. Deloitte’s prior reports for 2024 and 2025 were unqualified but included a going concern explanatory paragraph, indicating substantial doubt about LanzaTech’s ability to continue operating.

The company also disclosed material weaknesses in internal control over financial reporting across 2024 and 2025, covering complex transactions, revenue recognition, and multiple framework components such as control activities and monitoring. While there were no disagreements or restatements, the combination of a going concern paragraph and persistent control weaknesses is a material risk indicator for investors evaluating financial statement reliability.

8-K Event Classification

2 items: 4.01, 9.01

2 items

Item 4.01 Changes in Registrant's Certifying Accountant Governance

The company changed its independent auditing firm, which may involve disagreements on accounting matters.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Key Terms

going concern, material weaknesses, internal control over financial reporting, reportable events, +1 more

5 terms

going concern financial

"each report contained an explanatory paragraph regarding substantial doubt about the Company’s ability to continue as a going concern"

A going concern is a business that is expected to continue its operations and meet its obligations for the foreseeable future, rather than shutting down or selling off assets. This assumption matters to investors because it indicates stability and ongoing profitability, making the business a more reliable investment. Think of it as believing a restaurant will stay open and serve customers, rather than closing down suddenly.

material weaknesses financial

"the Company identified material weaknesses in internal control over financial reporting"

Material weaknesses are significant flaws in a company’s systems for ensuring its financial reports are accurate and reliable. Like a broken lock on a safe, they increase the chance that financial statements contain big errors or omissions, which can mislead investors about performance and risk; discovering one often raises questions about management oversight, may lead to restated results, and can affect investor confidence and a company’s valuation.

internal control over financial reporting financial

"material weaknesses in internal control over financial reporting related to (i) the accounting for complex transactions"

Internal control over financial reporting is a company’s system of procedures and checks designed to make sure its financial statements are accurate and complete, like a set of guardrails and verification steps that catch mistakes or fraud before numbers are published. Investors care because strong controls make reported results more trustworthy, lower the risk of surprise restatements or regulatory problems, and give greater confidence when valuing the company or comparing it to peers.

reportable events regulatory

"there were no “reportable events” (as defined in Item 304(a)(1)(v) of Regulation S-K), except as previously disclosed"

independent registered public accounting firm financial

"dismissal of Deloitte as the Company’s independent registered public accounting firm"

An independent registered public accounting firm is an outside accounting company officially registered with the government regulator to examine and report on a public company's financial records and controls. Investors treat its reports like an impartial inspector’s certificate — they add credibility to financial statements, help spot errors or misleading claims, and reduce the risk that shareholders are relying on unchecked or biased numbers.

Understanding 8-K Material Events →

04/17/2026 - 05:22 PM

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): April 10, 2026

LanzaTech Global, Inc.

(Exact name of registrant as specified in its charter)

Delaware

001-40282

92-2018969

(State or other jurisdiction
of incorporation)

(Commission File Number)

(I.R.S. Employer
Identification No.)


8045 Lamon Avenue, Suite 400 Skokie, Illinois						60077
(Address of principal executive offices)						(Zip Code)

(847) 324-2400

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

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


☐			Written communication 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-commencements 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:

Title of each class

Trading Symbols

Name of each exchange on which registered

Common Stock, par value $0.0000001 per share

LNZA

The Nasdaq Stock Market LLC

Warrants to purchase Common Stock

LNZAW

The Nasdaq Stock Market LLC


☐			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).


☐			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.

EXPLANATORY NOTE

This Amended Current Report on Form 8-K/A (this “Form 8-K/A”) amends the current report on Form 8-K that was filed by LanzaTech Global, Inc. (the “Company”) with the U.S. Securities and Exchange Commission (the “SEC”) on April 16, 2026, reporting the Company’s decision to: (a) dismiss Deloitte & Touche LLP (“Deloitte”) as its independent registered public accounting firm; and (b) engage BDO USA, P.C. (“BDO”) as its independent registered public accounting firm for the fiscal year ending December 31, 2026. The Company provided Deloitte with a copy of the disclosures made below in Item 4.01 and requested that Deloitte furnish the Company with a letter addressed to the Securities and Exchange Commission stating whether or not it agrees with the statements made below in Item 4.01. This Form 8-K/A is being filed to provide a copy of the letter from Deloitte, dated April 17, 2026, which is included with this Form 8-K/A as Exhibit 16.1.

Item 4.01 Changes in Registrant’s Certifying Accountant.

(a) Dismissal of Independent Registered Public Accounting Firm

On April 10, 2026, upon the recommendation and approval of the Audit Committee of the Board of Directors (the “Audit Committee”), the Board of Directors of LanzaTech Global, Inc. ratified and approved the dismissal of Deloitte as the Company’s independent registered public accounting firm, effective April 10, 2026.

Deloitte’s reports on the Company’s consolidated financial statements for the fiscal years ended December 31, 2025 and 2024 did not contain an adverse opinion or disclaimer of opinion and were not qualified or modified as to uncertainty, audit scope, or accounting principles, except that each report contained an explanatory paragraph regarding substantial doubt about the Company’s ability to continue as a going concern.

During the Company’s fiscal years ended December 31, 2025 and 2024, and the subsequent interim period through April 10, 2026, there were no disagreements (as defined in Item 304(a)(1)(iv) of Regulation S-K and its related instructions) between the Company and Deloitte on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, which, if not resolved to the satisfaction of Deloitte, would have caused Deloitte to make reference to the subject matter of the disagreement in its reports on the Company’s consolidated financial statements.

During the Company’s fiscal years ended December 31, 2025 and 2024, and the subsequent interim period through April 10, 2026, there were no “reportable events” (as defined in Item 304(a)(1)(v) of Regulation S-K), except as previously disclosed in the Company’s Annual Report on Form 10-K for the years ended December 31, 2024, where the Company identified material weaknesses in internal control over financial reporting related to (i) the accounting for complex transactions and estimates requiring significant judgment and (ii) revenue recognition, and in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, where the Company identified deficiencies in the Company’s internal control over financial reporting that constituted material weaknesses associated with multiple components of the Committee of Sponsoring Organizations of the Treadway Commission Internal Control - Integrated Framework, including control activities, monitoring, risk assessment, and information and communication. The Company and the Audit Committee have discussed the material weaknesses with Deloitte and have authorized them to respond fully to inquiries of the successor independent registered public accounting firm concerning such material weaknesses. Such material weaknesses did not result in any restatement of the Company’s financial statements and did not give rise to any disagreement between the Company and Deloitte.

The Company provided Deloitte with a copy of the above disclosures and requested that Deloitte furnish the Company with a letter addressed to the SEC stating whether they agree with the statements made by the Company in such disclosures and, if not, stating the respects, if any, in which they do not agree with such statements. Attached as Exhibit 16.1 is a copy of Deloitte’s letter, dated April 17, 2026 stating that they are in agreement with the statements above.

(b) Engagement of New Independent Registered Public Accounting Firm

On April 10, 2026, upon the recommendation and approval of the Audit Committee, the Board of Directors of the Company ratified and approved the engagement of BDO as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2026, effective April 10, 2026.

During the Company’s fiscal years ended December 31, 2025 and 2024, and the subsequent interim period through April 10, 2026, neither the Company nor anyone on its behalf consulted with BDO regarding either:

(i) the application of accounting principles to a specified transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Company’s consolidated financial statements, and neither a written report nor oral

advice was provided to the Company that BDO concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing, or financial reporting issue; or

(ii) any matter that was the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-K and its related instructions) or a reportable event (as described in Item 304(a)(1)(v) of Regulation S-K).

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits


Exhibit No.						Description

16.1						Letter from Deloitte & Touche LLP to the Securities and Exchange Commission dated April 17, 2026.
104						Cover Page Interactive Data File (formatted as Inline XBRL)

SIGNATURES

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.


	LANZATECH GLOBAL, INC.

Dated: April 17, 2026	By:	/s/ Maryann Maas
	Name:	Maryann Maas
	Title:	Interim General Counsel

Source: View Original Filing on SEC EDGAR

FAQ

Why did LanzaTech Global (LNZA) file this amended 8-K/A?

LanzaTech filed the amendment to add a letter from Deloitte & Touche LLP. Deloitte’s letter, dated April 17, 2026, states it agrees with LanzaTech’s disclosures about Deloitte’s dismissal and related matters described under the auditor change item.

What auditor changes did LanzaTech Global (LNZA) disclose?

On April 10, 2026, LanzaTech’s board dismissed Deloitte & Touche LLP as its independent registered public accounting firm and approved engaging BDO USA, P.C. as its new independent auditor for the fiscal year ending December 31, 2026.

Did Deloitte’s reports on LanzaTech (LNZA) include a going concern warning?

Yes. Deloitte’s reports on LanzaTech’s consolidated financial statements for the years ended December 31, 2024 and 2025 contained an explanatory paragraph highlighting substantial doubt about the company’s ability to continue as a going concern, even though the opinions were otherwise unqualified.

What internal control issues has LanzaTech Global (LNZA) reported?

LanzaTech identified material weaknesses in internal control over financial reporting in its 2024 and 2025 annual reports. These related to accounting for complex transactions, revenue recognition, and multiple Internal Control–Integrated Framework components such as control activities, monitoring, risk assessment, and information and communication.

Were there disagreements between LanzaTech (LNZA) and Deloitte before the auditor change?

The company states there were no disagreements with Deloitte on accounting principles, financial statement disclosure, or audit scope and procedures during 2024, 2025, and through April 10, 2026, that would have required reference in Deloitte’s audit reports.

Did LanzaTech (LNZA) or Deloitte restate any financial statements due to control weaknesses?

LanzaTech reports that the identified material weaknesses in internal control over financial reporting did not lead to any restatement of its financial statements and did not cause disagreements with Deloitte on the underlying accounting or disclosures.

Filing Exhibits & Attachments

5 documents