DOR Taxation web site

Secure Messaging and Telephone

Send a Message through your Revenue Online Account. Use it any time of day.

Find out how to do it.


Call Us With Your Tax Matters:
(303) 238-SERV (7378)

Customer Service Representatives are available Monday through Friday, 8 a.m. to 4:30 p.m.

Refund Information

Hearing or Speech Impaired:  Relay Colorado

  • TTY Telephone Users: 1-800-659-2656
  • Voice Telephone Users: 1-800-659-3656

To use this service, dial the appropriate number above. Give the Relay Colorado agent the number that you would like to call. The Relay Colorado agent will stay on the line to relay the information/conversation to you.

Other Helpful Numbers

  • EFT/Electronic Payment Help: (303) 205-8333
  • Fuel Tax/IFTA Helpline:  (303) 205-8205
  • Tax Auditing and Compliance: (303) 866-3711 
  • Office Collections: (303) 205-8291
  • Fair Share/Discovery: (303) 205-8292
  • Report Tax Evasion or Fraud:  (303) 205-8262