Company Update

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 12, 2020 ​ INTERNATIONAL BANCSHARES CORPORATION (Exact name of registrant as specified in its charter) ​ ​ ​ ​ ​ ​ Texas ​ 000-9439 ​ 74-2157138 (State or other jurisdiction ​ (Commission File ​ (IRS Employer of incorporation) ​ Number) ​ Identification No.) ​ ​ ​ ​ ​ ​ ​ 1200 San Bernardo , Laredo , Texas ​ 78040-1359 ​ ​ (Address of principal executive offices) ​ (Zip Code) ​ ​ Registrant's telephone number, including area code ( 956 ) 722-7611 ​ None (Former name or former address, if changed since last report) ​ Securities registered pursuant to Section 12(b) of the Act: ​ ​ ​ ​ ​ ​ ​ Title of Each Class: ​ Trading Symbol (s): ​ Name of each exchange on which registered: Common Stock , $1.00 par value ​ IBOC ​ NASDAQ ​ 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 (see General Instruction A.2.below): ​ ☐ 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)) ​ 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 12, 2020, the Board of Directors of International Bancshares Corporation (“IBC”) approved the extension of IBC’s stock repurchase program by authorizing the repurchase of up to $50 million of IBC common stock during the twelve month period commencing on March 16, 2020 (previous annual stock repurchase programs began on April 9). As of the close of business on March 12, 2020, IBC also had approximately $10 million that remains available under last year’s repurchase program, which began on April 9, 2019, and which IBC’s Board also extended during its March 12, 2020 meeting to end on the day after the third full business day following IBC’s filing of its Form 10-Q for the quarter ending March 31, 2020, pursuant to IBC’s Statement of Company Policy on Securities Trades by Directors, Officers and Employees. ​ All of the information furnished in Item 8.01 of this report and the accompanying exhibit is also intended to be included under “Item 7.01 — Regulation Fair Disclosure” and shall not be deemed to be “filed” for the purposes of Section 18 of the Securities and Exchange Act of 1934, as amended, is not subject to the liabilities of that section and shall not be incorporated by reference in any filing under the Securities Act of 1933, as amended. ​ 2 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. ​   INTERNATIONAL BANCSHARES CORPORATION   (Registrant)         ​ By: /s/ Dennis E. Nixon ​   Dennis E. Nixon, President and     CEO     March 16, 2020   ​ ​ ​ 3