Contact Us By Phone & Fax


    Before you call, we encourage you to try one of these self service options:


    Call the Taxpayer Helpline

    (303) 238-7378

    Taxpayer Service Representatives are available (except on state holidays)
    Monday through Friday, 8:00 a.m. to 4:30 p.m. MT

    Additional Contact Phone Numbers

    Send Us a Fax

    Did you know you can fax the Department? You can send a wide variety of forms to the following dedicated teams:


    Hearing or Speech Impaired Relay Services

    To use this service, dial the appropriate number below. 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