Sole Proprietorship Tax Deadlines in California
Federal and state filing dates, extensions, and estimate schedules for 2026.
California filing deadline
Sole proprietors file with personal return; automatic extension to file.
Due: Apr 15, 2026
Extension: Oct 15, 2026
Form: Form 540 / 540NR
Estimated payments
Estimated payment dates: Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Jan 15, 2027.
Due: Apr 15, 2026
FAQ
Does California require Sole Proprietorship estimated payments?
Estimated payments are scheduled for Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Jan 15, 2027.
Where can I file California Sole Proprietorship taxes?
Use California Franchise Tax Board resources at https://www.ftb.ca.gov for forms and filing instructions.