C Corporation Tax Deadlines in California
Federal and state filing dates, extensions, and estimate schedules for 2026.
California filing deadline
Automatic 7-month extension for most corporations in CA.
Due: Apr 15, 2026
Extension: Nov 15, 2026
Form: Form 100
Estimated payments
Estimated payment dates: Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Dec 15, 2026.
Due: Apr 15, 2026
FAQ
Does California require C Corporation estimated payments?
Estimated payments are scheduled for Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Dec 15, 2026.
Where can I file California C Corporation taxes?
Use California Franchise Tax Board resources at https://www.ftb.ca.gov for forms and filing instructions.