Mail a Form

CDOR Mailing Address 
This address and zip code are exclusive to the Colorado Department of Revenue and a street address is not required. 
Colorado Department of Revenue
Denver, CO 80261


Income Tax
Use the following "Plus-4" numbers to get returns and payments routed to the correct tax office within the Department:
Form Address

104, 104CR, 104PN, 104X
105
106, 106CR, 107
112, 112C, 112CR, 112SF, 112X
DR 0617
DR 1778

If you are submitting the form with a check or payment:
Colorado Department of Revenue
Denver, CO 80261-0006
 
If you are submitting the form without a check or payment:
Colorado Department of Revenue
Denver, CO 80261-0005

DR 104BEP
DR 108
DR 0158-C, DR 0158-F, DR 0158-I, DR 0158-N
DR 0900, DR0900C, DR0900P

Colorado Department of Revenue
Denver, CO 80261-0008
All other income tax related forms
Colorado Department of Revenue
Denver, CO 80261-0008
Notice of deficiency, tax protests, delinquent tax payments
Colorado Department of Revenue
Denver, CO 80261-0004

 

All Other Taxes including Sales and Withholding
Use the following "Plus-4" numbers to get returns and payments routed to the correct tax office within the Department:

  • 80261-0004: notice of deficiency, tax protests, delinquent tax payments
  • 80261-0009: withholding tax, annual withholding reconciliations and miscellaneous business and excise taxes (e.g., liquor, cigarette, tobacco, fuel, heavy truck sales, aviation, prepaid wireless E911 surcharge)
  • 80261-0013: sales tax, use tax, county lodging, county short term rental, local marketing district tax, rural transportation authority

Certified Mail
Although certified mail gives the option to receive a return receipt, sending a tax return as certified mail may delay processing because the mail cannot be run through any automated process. Taxpayers may actually get their return recorded in our system quicker with just a postmark on the envelope.

Proper Postage on the Envelope
The U.S. Postal Service will not deliver mail without the proper postage. If a filer mails in a return without proper postage, it will be returned to sender. This is especially important for those filing on or very near the filing deadlines of April 18 or October 16. When filing an income tax return through our Revenue Online service, www.Colorado.gov/RevenueOnline, taxpayers can save the postage and envelope, while also being assured their return was received on time.