Key Tax Deadlines for S Corp by State

S Corporation tax deadlines vary by state but follow these general patterns: Federal Deadlines: Form 1120S due March 15 (or September 15 with extension). Schedule K-1s to shareholders by March 15. State-Specific Variations: California: Form 100S due March 15, $800 minimum franchise tax. New York: Form CT-3-S due March 15, additional NYC requirements if applicable. Texas: Franchise tax reports due May 15, though many S Corps qualify for no tax due. Florida: No state income tax, but annual report due May 1. Illinois: Form 1120-ST due March 15. Common State Deadlines: Most states align with federal Form 1120S deadline (March 15). Some states require separate extensions even if federal extension is filed. State K-1 distribution deadlines typically match federal requirements. Key Considerations: Multi-state S Corps may have different deadlines in each state. Some states don't recognize S elections and tax as C Corps. Extension deadlines are typically 6 months from original due date. Always verify current year deadlines as they can change with holidays or legislation.