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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

For the fiscal year ended December 31, 2025

Commission file number 1-9861

M&T BANK CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code:

716-635-4000

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

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes x No o

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months, and (2) has been subject to such filing requirements for the past 90 days. Yes x No o

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months. Yes x No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

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. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. x

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. o

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). o

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes o No x

Aggregate market value of the Common Stock, $0.50 par value, held by non-affiliates of the registrant, computed by reference to the closing price as of the close of business on June 30, 2025: $29,618,092,321.

Number of shares of the Common Stock, $0.50 par value, outstanding as of the close of business on February 13, 2026: 149,000,252 shares.

Documents Incorporated By Reference:

(1) Portions of the Proxy Statement for the 2026 Annual Meeting of Shareholders of M&T Bank Corporation in Parts II and III.

Auditor Firm Id: 238 Auditor Name: PricewaterhouseCoopers LLP Auditor Location: Buffalo, NY, United States

M&T BANK CORPORATION

Form 10-K for the year ended December 31, 2025

CROSS-REFERENCE SHEET

Glossary of Terms

The following listing includes acronyms and terms used throughout the document.

PART I