C Corporation Tax Deadlines in Washington
Federal and state filing dates, extensions, and estimate schedules for 2026.
Washington filing deadline
No state individual income tax. Other business taxes may apply.
Due: N/A
Form: N/A
Estimated payments
No state estimated payment schedule listed.
Due: N/A
FAQ
Does Washington require C Corporation estimated payments?
Estimated payments are not typically required at the entity level, but confirm with Washington Department of Revenue.
Where can I file Washington C Corporation taxes?
Use Washington Department of Revenue resources at https://dor.wa.gov for forms and filing instructions.