Is This Really the Colorado Department of Revenue?

The Colorado Department of Revenue (CDOR) will not call or email you asking for personally identifiable information (PII). Even if the caller ID or return email address says it is CDOR or the State of Colorado, be wary of requests for PII. Unsolicited phone and email requests for personally identifiable information are often government imposter scams. As a result of this type of scams, it is understandable that you may worry that you are receiving a legitimate request for information from the Department. 

How to Recognize CDOR 

If we need additional information, we will send a letter to you via standard mail. The letter will be on CDOR letterhead (see a sample of CDOR official correspondence).

Some letters from the Department requested information be sent to the Colorado Department of Revenue, so we may request you verify your identity if either you or someone else has filed a return under your name. If this happens, you should also be sure to verify whether your spouse or a tax professional has filed a return on your behalf. It is possible a legitimate return has been filed. Sometimes taxpayers are unaware the return has already been submitted by someone they have authorized to file the return.

If you receive a letter from us, please respond quickly to ensure that you get your refund to you as soon as possible. Refunds will be delayed until CDOR receives the requested information. If you do not respond, your return will not be processed. 

Possible Documents or Information the Department May Request in Support of a Colorado Tax Refund

The Department may ask for the following documentation to verify your identity

  • Copy of Driver License or ID
  • Copy of a document containing your name and address ​​
  • Copy of W-2(s) and/or 1099(s) claiming Colorado tax withholding
  • Refund Amount.
  • ​​Validation Key

Revenue Online is the fastest, safest and most secure means to upload requested documents. For instructions and additional information, visit the Revenue Online Instructions web page and scroll down to "Additional Services."