Colorado LLC Tax Deadlines 2026
Complete guide to LLC filing dates, extensions, estimated payment schedules, and required forms in Colorado for the 2026 tax year. Colorado imposes a state income tax, so LLC entities must file both federal and state returns.
Colorado LLC filing deadline
Calendar-year due date follows federal timing for pass-through entities.
Due: Mar 16, 2026
Extension: Sep 15, 2026
Form: State LLC return
Estimated payments
No state estimated payment schedule listed.
Due: N/A
Colorado LLC Tax Calendar at a Glance
| Event | Date |
|---|---|
| Filing deadline | Mar 16, 2026 |
| Extension deadline | Sep 15, 2026 |
FAQ
When is the LLC tax filing deadline in Colorado for 2026?
The Colorado LLC tax return is due Mar 16, 2026 for the 2026 tax year. An extension is available until Sep 15, 2026.
Does Colorado require LLC estimated tax payments?
Estimated payments are not typically required at the entity level for LLC in Colorado, but confirm with Colorado Department of Revenue.
What form do I file for a LLC in Colorado?
LLC entities in Colorado file using Form State LLC return. You can download the form from Colorado Department of Revenue at https://tax.colorado.gov.
Can I get an extension for my Colorado LLC tax return?
Yes. Colorado allows an extension for LLC returns until Sep 15, 2026. Note that an extension gives you more time to file, not more time to pay — any tax owed is still due by the original deadline of Mar 16, 2026.
What are the penalties for filing late in Colorado?
Colorado typically charges a failure-to-file penalty (usually 5% of unpaid tax per month, up to 25%) and a failure-to-pay penalty (usually 0.5-1% per month). Interest also accrues on unpaid balances. Filing for an extension by the original deadline avoids the failure-to-file penalty but not the failure-to-pay penalty.
Where can I file Colorado LLC taxes?
File through Colorado Department of Revenue. Visit https://tax.colorado.gov for e-filing options, downloadable forms, and payment portals.
Colorado Estimated Tax Payments
View the full quarterly estimated payment schedule for Colorado, including all entity types and payment methods.
View Colorado estimated payments →