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.
Please note: Income is generally considered to be the gross amount you made and not the net amount. If you are a nonresident for Colorado but have a rental property there, Colorado will want to see a return from you even though your net rental income is zero.
