Use the DR 0104X, Amended Colorado Income Tax Return, to correct the individual income tax return you already filed for the specific tax year. Please refer to the 104 Book for line-by-line instructions and details about specific additions, subtractions, and tax credits. After completing the Amended Colorado Income Tax Return, file it with a computer, smartphone, or tablet on Revenue Online to use our free and secure service. By filing your return electronically, you significantly reduce the chance of errors. If you cannot file electronically for any reason, mail the following form as instructed in the directions of the DR 0104X. Complete the return with the corrected amounts, as amended.
