Who Must File This Tax Return
Each year you must evaluate if you should file a Colorado income tax return. Generally, you must file this return if you are required to file a federal income tax return with the IRS for this year or will have a Colorado income tax liability for this year and you are:
• A full-year resident of Colorado, or
• A part-year Colorado resident who received taxable income while residing here or
• Not a resident of Colorado, but received income from sources within Colorado.
Colorado residents must file this return if they are required to file an income tax return with the IRS, even if they do not have a Colorado tax liability. Otherwise, the Department may file a return on your behalf and our return might not consider your unique tax situation. Also, the only way to determine if you are entitled to a refund is to file a return.