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
- Collections: 303-205-8291
- Collections Hours of Operation:
- Monday-Friday from 8:00 a.m. to 4:30 p.m.
- Closed from 12:00-1:00 p.m. daily for lunch
- Collections Hours of Operation:
- EFT/Electronic Payment: 303-205-8333
- Report Tax Evasion, Fraud or Scams: 303-205-8262
- Excise Tax Unit (Cigarette, Tobacco Products, Liquor): 303-205-6848
- Fuel Tax Unit (Fuel & IFTA): 303-205-8205
- Marijuana Information Line: 303-205-8287
- Bankruptcy: 303-866-3711
- Compliance: 303-866-3711
- Discovery: 303-205-8292
- Field Audit: 303-692-7981
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:
- Business Tax Accounting Section (BTAS): 303-205-2376
- Contractor Exemption Applications
- Certificate of Exemption for Nonprofits Applications
- Written requests for copies of exemption certificates
- 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