DOR Taxation web site

Correcting a Return

Tips for Filing Colorado fiduciary income tax amended returns

For fiduciary amended returns, use the 105 form as the amended return. File the amended return through Revenue Online.

  • Be sure to CLEARLY MARK the Amended Return checkbox at the top of these forms.
  • The place to indicate “amended return” is at the top of the 105 form and it reads: “Check here if this is an amended return for calendar year 2009 or other tax year.”
  • To ensure the 105 return will be noticed in our processing pipeline as amended when we receive them, write AMENDED RETURN in red across the top to draw attention to the return.