Colorado State Tax Guide
Click your state on the map to see filing deadlines, extension rules, refund tracking, and payment options for that state. States shown in gray are coming soon.
Hover or tab a state to see its name.
Colorado State Tax Guide
Extension rules
Extension type: Automatic State Extension
There is no state-specific form to request an extension, as the state of Colorado automatically provides the extension of time for individuals to file their personal tax returns with the state. Paperwork Needed: None. Your extension to file your final return (Form DR 0104) is already approved by default. To use the extension without getting hit by financial penalties, you must pay at least 90% of your actual net Colorado tax liability on or before April 15. - If you expect a refund: You do not need to do anything. You can safely wait until October 15 to file your paperwork. - If you owe money: You must calculate what you owe and send in that payment by April 15. If you pay less than 90% of your total liability, the automatic extension safety net breaks, and late penalties will apply.
If you owe tax: If you owe money: You must calculate what you owe and send in that payment by April 15. If you pay less than 90% of your total liability, the automatic extension safety net breaks, and late penalties will apply. If you owe Colorado state income tax, 90% of the tax liability must be paid by April 15th to avoid penalties.
If you owe $0: If you expect a refund: You do not need to do anything. You can safely wait until October 15 to file your paperwork. Paperwork Needed: None. Your extension to file your final return (Form DR 0104) is already approved by default.
How to request
- Online: If you owe money - make an extension payment : Extension payment (DR0158I)
To use the extension without getting hit by financial penalties, you must pay at least 90% of your actual net Colorado tax liability on or before April 15. - If you expect a refund: You do not need to do anything. You can safely wait until October 15 to file your paperwork. - If you owe money: You must calculate what you owe and send in that payment by April 15. If you pay less than 90% of your total liability, the automatic extension safety net breaks, and late penalties will apply.
Colorado — Income tax due dates & filing extension
Relevant Links
Colorado Key deadlines (tax year 2025, return filed in 2026)
- Filing deadline: Apr 15, 2026
- Extension request deadline: Apr 15, 2026 — Automatic unless you owe a tax liability then the deadline to file is April 15, 2026
- Extended return deadline: Oct 15, 2026 (6-month extension)
- Payment deadline: Apr 15, 2026
- Differs from federal: No
To avoid a late payment penalty, you must pay at least 90% of your total Colorado tax liability by April 15. If you pay: • 90% or more by April 15 → No late payment penalty, provided you file by October 15 and pay the remaining balance with your return. • Less than 90% by April 15 → You may owe both penalties and interest on the unpaid amount.
If the due date for filing your return falls on a Saturday, Sunday, or legal holiday, your return is due by the next regular working day.
Estimated payments
- Apr 15, 2026
- Jun 15, 2026
- Sep 15, 2026
- Jan 15, 2027
October 15, 2026 (6-month extension)
Payment rules
To use the extension without getting hit by financial penalties, you must pay at least 90% of your actual net Colorado tax liability on or before April 15. - If you expect a refund: You do not need to do anything. You can safely wait until October 15 to file your paperwork. - If you owe money: You must calculate what you owe and send in that payment by April 15. If you pay less than 90% of your total liability, the automatic extension safety net breaks, and late penalties will apply.
Official payment portal
Payment options
Payment plan availability
Available: Yes
Filing forms
Regular filing
- Form DR 0104 - Colorado state tax return
- DR0158I - Extension payment
Colorado Refund Tracking
Processing time: Check Revenue Online for current status
Do I need to file?
Paperwork Needed: None. Your extension to file your final return (Form DR 0104) is already approved by default. There is no state-specific form to request an extension, as the state of Colorado automatically provides the extension of time for individuals to file their personal tax returns with the state.
- Residents: Paperwork Needed: None. Your extension to file your final return (Form DR 0104) is already approved by default.
- Part-year residents: Paperwork Needed: None. Your extension to file your final return (Form DR 0104) is already approved by default.
- Nonresidents: Paperwork Needed: None. Your extension to file your final return (Form DR 0104) is already approved by default.
Filing methods
Online filing
If you owe money - make an extension payment : Extension payment (DR0158I)
Mail filing
There is no state-specific form to request an extension, as the state of Colorado automatically provides the extension of time for individuals to file their personal tax returns with the state.
