Colorado Filing Due Date: Individual income tax returns are due by April 15, in most years — or by the 15^th day of the 4^th month following the end of the taxable year (for fiscal year filers).

Extended Deadline with Colorado Tax Extension: Colorado offers a 6-month extension, which moves the filing deadline to October 15 (for calendar year filers).

Colorado Tax Extension Form: Colorado’s tax extensions are paperless, so there is no state extension application or written request to submit. You will automatically receive a Colorado tax extension if at least 90% of your state tax liability is paid by the original due date.

Colorado Extension Payment Requirement: An extension of time to file is not an extension of time to pay your Colorado income tax. All state tax payments are due by the original deadline of the return. Any Colorado tax not paid by the proper due date will be subject to penalties and interest. You can make a Colorado extension payment with Form DR 0158-I, or pay electronically through Colorado’s Revenue Online portal: www.colorado.gov/revenueonline

Colorado Tax Extension Tips: Use the worksheet on Form 0158-I to see if you owe Colorado tax and need to make an extension payment.

Do not file Form DR 0158-I if you make your Colorado extension payment electronically.