Using Revenue Online? 

Call the Taxpayer Help Line

Tax Information: (303) 238-7378

  • Taxpayer Service Representatives are available Monday through Friday, 8:00 a.m. to 4:30 p.m.

Other Contact Phone Numbers

Hearing or Speech Impaired:  Relay Colorado

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

Assistance in Person (Service Centers)

Taxpayer Service Centers:
  •  Can assist with general information regarding taxes
  •  Can provide tax account registration assistance
  •  Can provide tax filing assistance
  •  Perform enforcement and business seizure activities due to failure to file taxes, and monitor tax delinquencies.