Correcting a Return
Any adjustment made on federal amended returns must be reported and the Colorado income tax should be adjusted accordingly on the Amended Colorado C-Corporation Return (112X) which is available on the Colorado Corporation Income Tax Forms page. You must use the appropriate year 112X form because the lines change on each year's form and forms for other tax years will not necessarily match the year you mean to amend. Additionally, any adjustments made by the Internal Revenue Service must also be reported to Colorado on the 112X. If the corporation operates in two or more states, the corporation can mail the IRS revenue agent's report instead of the Colorado 112X. Please include the Colorado account number on the report.