X0609 4 2026-10-21 0000315709 INTERNATIONAL BANCSHARES CORP IBOC 0001060529 SANCHEZ ANTONIO R JR false 1360 POST OAK BLVD STE 2400 HOUSTON TX 77056 true false true false 0 Common Stock 1805554 D Common Stock 9000 I Held by Grandchildren's Trust Common Stock 447439 I Held in Partnership Common Stock 2026-10-21 4 J 0 25000 0 D 1207245 I Held in Trust On October 21, 2026, a trust for which the reporting person serves as co-trustee distributed 25,000 shares to a beneficiary of the trust. The reporting person disclaims beneficial ownership of the securities except to the extent of the pecuniary interest therein, if any. /s/ ANTONIO R. SANCHEZ JR. 2026-10-23