How to Prepare and File a Colorado Tax Amendment Form

Colorado State Taxes
amend Colorado taxes
Colorado
"The Centennial State"

When Should I Prepare and File My Colorado Tax Amendment?

You should file an amended tax return and receive a refund 4 years after the original filing date or 3 years after payment of tax, whichever is later.

How Do I Correct My Accepted Colorado Tax Return or File a Tax Amendment in Colorado?

You will need to file a Colorado tax amendment form in order to correct your accepted Colorado tax return. Here's how:

  1. Download and complete Form 104X.
  2. Print out the amendment form and mail it to this address: Colorado Department of Revenue, Denver, CO 80261-0005.

Colorado State Tax Amendment Forms (Download, Print Out, Complete, and Mail)

Fill out Form 104X for the corresponding year.

Form (Tax Year) Description
Form 104X (2016) Amended Colorado Individual Income Tax Return Form and Instructions
Form 104X (2015) Amended Colorado Individual Income Tax Return Form and Instructions
Form 104X (2014) Amended Colorado Individual Income Tax Return Form and Instructions
Form 104X (2013) Amended Colorado Individual Income Tax Return Form and Instructions
Form 104X (2012) Amended Colorado Individual Income Tax Return Form and Instructions
Form 104X (2011) Amended Colorado Individual Income Tax Return Form and Instructions

How Do I Check the Status of My Colorado Tax Amendment?

You can call the Colorado Department of Revenue at 303-238-SERV (7378).

Penalties, Interest, and Fees

The state of Colorado computes interest on unpaid taxes as well as owed tax returns.

Interest Rates on Unpaid Tax or Tax Returns

Year Tax paid without billing or within 30 days of billing After 30 days since billing
2017 3% 6%
2016 3% 6%
2015 3% 6%
2014 3% 6%
2013 3% 6%
2012 3% 6%
2011 3% 6%

 

There are penalties for late payment, but if at least 90% of the tax was paid by the deadline then there is no penalty assessed and there is only interest charged on the tax owed, under the condition that the tax would be paid in full by October 15.

Where Do I Mail My Amended Colorado Tax Return?-Colorado Mailing Address:

Colorado Department of Revenue
Denver, CO 80261-0005

Colorado Department of Revenue Phone Number: 303-238-SERV (7378)

Colorado Department of Revenue

Where Do I Find More Colorado Tax Information?

How Do I Prepare, File Only My Colorado Tax Return?

Where is my Colorado State Tax Refund?

How to File a Colorado Tax Extension

Colorado State Taxes

What If I Need To Correct My Federal Return or File a Federal Tax Amendment?

Learn how to file a federal tax amendment.