IBC amends bylaws to require 3% ownership for derivative suits, adds exclusive forum and jury waiver

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. On August 6, 2025, following the effectiveness of amendments to the Texas Business Organizations Code (“TBOC”), the Board of Directors of International Bancshares Corporation (“IBC”) approved and adopted the Second Amended and Restated By-Laws of IBC (the “By-Laws”) in order to specify that a shareholder or group of shareholders may not institute or maintain a derivative proceeding unless that shareholder or group of shareholders beneficially own three percent of IBC’s issued and outstanding common stock, par value $1.00 per share, at the time such derivative proceeding is instituted. In addition, the By-Laws were amended to provide that the Texas Business Court located in the Fourth Business Court Division or, if such court lacks jurisdiction the United States District Court for the Southern District of Texas, or if such court lacks jurisdiction the state district court of Webb County will be the sole