Please remember that you must claim the state sales tax refund (TABOR refund) when filing your state income tax return. If you claimed a 2023 refund, the TABOR refund will be combined and issued out with your refund. Unlike the 2022 Colorado cashback, no separate check will be issued. 


Individual Income Tax | Due Dates & Filing Extension

Filing Due Date

Monday, April 15, 2024

Filing Extension

If you cannot file your Colorado income tax return by the deadline, you may take advantage of the state‚Äôs automatic six-month extension of time to file. There is no form to fill out to notify the Department of Revenue that you are taking the extension, however, there is no extension for tax due.

If you owe Colorado state income tax, 90% of the tax liability must be paid by April 15th to avoid penalties. Any remaining balance due would be subject to interest only. You need to either pay through Revenue Online or submit your payment with the Extension Payment Form (DR 0158-I). Once you have paid at least 90% of your income tax liability by April 15th, you will have until October 15th to file your Colorado Income Tax Return (DR 0104).

If you expect to get a Colorado income tax refund this year, but do not file your return by the due date, you can also use the extension to file your return by October 15th.

If the due date or extension date falls on a weekend or legal holiday, the return or payment will be due the next business day.