Colorado Income Tax Returns, Forms and Calculators Prepare And efile Your 2022, 2023 Colorado State Tax Return. Learn How To Prepare And efile Your State Of Colorado Income Tax Return with your Federal Tax Return. Find CO Tax Forms, Tax Deadlines, etc. How to File an Colorado Income Tax Return Tax Extension How and When To Prepare and File an Colorado Tax Extension. Should You File an Colorado Tax Return or Extension. Deadlines. Colorado Income Tax Payment Options. Online by Check. How To Pay Colorado Income Taxes Online or via Check. Options to Pay Income Taxes. Mailing Addresses for CO Returns. Tax Day and Deadlines For Colorado Income Taxes Colorado State Income Deadlines. The Tax Day Is Almost Always The Same Date as the IRS Deadline. Extension Deadline and Amendment Information. Your Colorado Tax Refund Status? Find Out Where Your Money Is. After Your Filed Your Colorado Taxes You Can Check Your Tax Refund Status Here. Colorado Will Post This Once Your Return Got Accepted Colorado Income Tax Forms By Tax Year. e-File Your Taxes. Income Tax Forms For The State of Colorado. Forms That You Can e-File and Forms you Can Fill Out here on eFile.com. Prepare Now. Colorado Income Brackets, Rates and Standard Deductions Colorado or CO Income Tax Rates, Income Brackets, Standard Deductions, and Forms by various Tax Years. Prepare and File A Colorado Income Tax Amendment Form on eFile.com Instructions on How to Complete and Sign a Colorado Tax Amendment Form. Download, Print the Form 104X and Mail It To the CO State Tax Agency. Calculate, Estimate Your Colorado Income Taxes The Colorado Income Tax Estimator Will Let You Calculate Your State Taxes For the Tax Year. The Federal or IRS Taxes Are Listed. Colorado Income Tax Return Instructions for eFile.com Arizona Income Tax Return Instructions and How To Prepare on eFile.com. Learn To Find CO Forms on eFile.com. TurboTax® is a registered trademark of Intuit, Inc. H&R Block® is a registered trademark of HRB Innovations, Inc.