Colorado Department of Revenue Contact Information
Need to reach the Colorado Department of Revenue? Here are all the ways to get help with sales tax registration, filing, payments, and compliance questions.
Main Contact Information
| General Tax Information | 303-238-7378 |
| Toll-Free | 1-800-886-7798 |
| Hours | Monday – Friday, 8:00 AM – 4:30 PM (Mountain) |
| Website | tax.colorado.gov |
| Revenue Online | colorado.gov/revenueonline |
Mailing Address
Colorado Department of Revenue
Taxpayer Service Division
P.O. Box 17087
Denver, CO 80217-0087
For physical delivery (FedEx, UPS, etc.):
Colorado Department of Revenue
1707 Cole Blvd, Suite 200
Lakewood, CO 80401
Specific Contact Numbers
| Sales and Use Tax Questions | 303-238-7378 |
| Business Registration | 303-238-7378 |
| SUTS Portal Support | 303-866-2371 |
| Collections | 303-205-8291 |
| Tax Forms | 303-238-3278 |
Online Services Available
Through Revenue Online and the SUTS portal, you can:
- Register for a sales tax license
- File and pay sales tax returns
- Register with participating home-rule cities
- Look up sales tax rates by address
- Update your business information
- View your account history
- Request copies of licenses
Access Revenue Online at: colorado.gov/revenueonline
SUTS Portal (Sales and Use Tax System)
The SUTS portal simplifies compliance with home-rule cities by offering:
- Single-point registration for participating cities
- Consolidated filing for multiple jurisdictions
- Rate lookup tools
SUTS Support: 303-866-2371
Email: dor_localgovsupport@state.co.us
Major Home-Rule City Contacts
These cities administer their own sales taxes separately:
Denver
720-913-9400
denvergov.org/treasury
Colorado Springs
719-385-5903
coloradosprings.gov/salestax
Aurora
303-739-7057
auroragov.org/salestax
Boulder
303-441-3051
bouldercolorado.gov/tax
Fort Collins
970-221-6780
fcgov.com/salestax
Lakewood
303-987-7651
lakewood.org/salestax
Many home-rule cities participate in SUTS for simplified registration and filing.
Forms and Publications
The Colorado DOR website provides downloadable forms and guides:
- Form CR 0100: Colorado Business Registration
- Form DR 0100: Colorado Retail Sales Tax Return
- Form DR 1002: Sales/Use Tax Rates Publication
Access all forms at: tax.colorado.gov/forms
Response Times
| Phone inquiries | Immediate (hold times vary) |
| Email inquiries | 3-5 business days typical |
| Online registration | Immediate to 5 business days |
| Mailed correspondence | 2-4 weeks |
For fastest service, use Revenue Online or call early in the week when hold times are typically shorter.
Related Colorado Guides
Rates and Fees
Current Colorado sales tax rates and how to look them up.
Business Licensing
CDOR handles sales tax — other agencies handle different licenses.
Interested in professional support? Learn about our filing assistance service for help with your Colorado sales tax application.