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
Dedicated Phone Support
- Collections: 303-205-8291
- Collections Hours of Operation:
- Monday-Thursday from 8:00 a.m. to 4:30 p.m.
- Friday 8:30 a.m. to 4:30 p.m.
- Collections Hours of Operation:
- EFT/Electronic Payment: 303-205-8333
- Sales & Use Tax System (SUTS) Support: 720-795-7759
Tax Unit Contact Phone Numbers
- Bankruptcy: 303-866-3711
- Compliance: 303-866-3711
- Discovery: 303-205-8292
- Excise Tax Unit (Cigarette, Liquor, Nicotine, Marijuana, and Tobacco Products): 303-205-8287
- Field Audit: 303-692-7981
- Fraud and Tax Evasion: 303-205-8262
- Fuel Tax Unit (Fuel & IFTA): 303-205-8205
- Special Event Sales Tax: 303-866-5643
Send Us a Fax
Did you know you can fax certain forms to the Department?
Registration Control: 303-866-4176
- Withholding Account Applications
- Power of Attorney Forms
- Third Party Access Requests
- E-Filer Attachment Forms
- NOTE: Be sure to include your attachments with the faxed form.
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