S Corporation Tax Deadlines in California

Federal and state filing dates, extensions, and estimate schedules for 2026.

California filing deadline

Automatic extension for CA S corporations.

Soon

Due: Mar 16, 2026

Extension: Sep 15, 2026

Form: Form 100S

Estimated payments

No state estimated payment schedule listed.

N/A

Due: N/A

FAQ

Does California require S Corporation estimated payments?

Estimated payments are not typically required at the entity level, but confirm with California Franchise Tax Board.

Where can I file California S Corporation taxes?

Use California Franchise Tax Board resources at https://www.ftb.ca.gov for forms and filing instructions.