DOR Taxation web site

Extensions

Colorado corporation income tax returns are due to be filed three-and-one-half months after the close of the corporation's tax year.  The tax year may not necessarily be a calendar year.

An automatic six-month extension of time to file is allowed for all taxpayers. However, an extension of time to file does not mean this is an extension of time to pay the tax.  If at least 90 percent fo the net tax liability is not paid by the original due date of the return, penalty and interest will be assessed.  If 90 percent or more of the net tax liability if paid by the original due date of the return and the balance is paid when the return is filed by the extension deadline date, only interest on the tax will be assessed.

Use voucher form DR 158-C which is included in the 112 Colorado Corporation Income Tax Booklet and is available as a single form on our Corporation Income Tax Forms Web page.

Pay Online

You can pay online through Revenue Online. Choose Business.

Pay by Mail
Mail the voucher to:
Colorado Department of Revenue
1375 Sherman St.
Denver, CO 80261