Income Tax | Corporation -- Account

A Colorado income tax account is created for the taxpayer the first time an income tax return is filed with the Department of Revenue. The Department establishes an eight-digit Colorado Account Number (CAN) which should be used on all future income tax filings. If a corporation also have an eight-digit CAN for a sales tax license/account or a wage withholding account, that is the same number that should be used on the income tax return.
Access your tax account information through Revenue Online. Taxpayers may access their account through the Department’s free service, Revenue Online. (Learn How to Sign Up for Access.)
The taxpayer creates a User ID and Password to access the account. Corporations may file an income tax return free of charge in Revenue Online. However, the taxpayer or an authorized representative must be logged into the account in Revenue Online to file the return. Taxpayers may opt to e-file through a paid tax professional or purchase tax software to complete and file returns.
Once you are inside your Colorado Department of Revenue tax account in Revenue Online, click on the specific tax account you want to view (COR for corporation income). You will see all of the filing periods for that tax type, including links to returns you have already filed and links to returns that should be filed.