Colorado Tax Deadlines

When are taxes due in Colorado?

Colorado state income tax returns for 2025 are generally due on April 15, 2026, aligning with the federal deadline. However, some entity types such as partnerships and S-corporations have earlier deadlines (March 16, 2026). Check the deadlines above for your specific entity type.

Does Colorado require estimated tax payments?

Yes, Colorado generally requires estimated tax payments if you expect to owe more than a certain threshold in state income tax. Payments typically follow a quarterly schedule. Visit the estimated payments page for Colorado for specific due dates.

What is the Colorado tax extension deadline?

Colorado generally grants a 6-month extension for filing state income tax returns, moving the deadline to October 15, 2026 for most individual filers. Note that an extension to file is not an extension to pay — any tax owed is still due by the original deadline.

What are the Colorado tax rates for 2026?

Colorado tax rates vary by income level and filing status. For the most current rates and brackets, visit Colorado Department of Revenue at https://tax.colorado.gov. Tax rates can change annually based on state legislation.

Does Colorado conform to federal due dates?

Many Colorado deadlines follow the federal calendar. Always confirm on Colorado Department of Revenue.

Where can I file Colorado tax forms?

Visit Colorado Department of Revenue at https://tax.colorado.gov for official forms and e-file options.