Sole Proprietorship Tax Deadlines in Colorado
Federal and state filing dates, extensions, and estimate schedules for 2026.
Colorado filing deadline
Business income reported on CO personal return.
Due: Apr 15, 2026
Extension: Oct 15, 2026
Form: Form DR 0104
Estimated payments
Estimated payment dates: Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Jan 15, 2027.
Due: Apr 15, 2026
FAQ
Does Colorado 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 Colorado Sole Proprietorship taxes?
Use Colorado Department of Revenue resources at https://tax.colorado.gov for forms and filing instructions.