Colorado severance tax returns are due on or before the 15th day of the fourth month following the end of the taxable year.
An automatic six-month extension of time for filing the Colorado severance tax return is allowed for all taxpayers. However, an extension of time to file is not an extension of time to pay the tax. If at least 90% of the net tax liability is not paid by the original due date of the return, penalty and interest will be assessed. If 90% or more of the net tax liability is paid by the original due date of the return and the balance is paid when the return is filed by the last day of the extension period, only interest will be assessed.
Use the DR 0021SA to make a payment that must be made by the original due date of the return to meet the 90% requirement.