Business Tax Return Extension Deadline 2024.  — in that case, you must file a 2023 tax return or extension request by march 15, 2024. You have right up until tax day to file for an extension.

 — there are 3 ways to get until october 15 to file your tax return. Sole proprietors and c corporations must file income tax returns by octobe r 15, 2024, i f they successfully applied for a tax extension.