You must file a Colorado income tax return if during the year you were:
- A full-year resident of Colorado, or
- A part-year resident of Colorado with taxable income during that part of the year you were a resident, or
- A nonresident of Colorado with Colorado source income,
AND
- You are required to file a federal income tax return, or
- You have a Colorado income tax liability for the year.
A Colorado resident is a person who has made a home in Colorado, or a person whose intention is to be a Colorado resident. The department will consider, among other things, Colorado voter registration, Colorado vehicle registration, Colorado driver license, school registration, property ownership and residence of spouse or children in determining intention to be a Colorado resident.
It is in your best interest to file a Colorado return even if you are expecting a refund. If you do not file a return and the Department has reason to believe you should, one may be filed on your behalf. Department-filed returns are prepared with the best available information. However, they may not take into account all factors of your unique tax situation and could result in a bill.