Contact Us

Contact Us by Email, Phone and Fax

Secure Messaging via Revenue Online- Revenue Online remains the fastest, safest and most secure way to communicate with the Colorado Department of Revenue - Taxation Division; however, representatives are not available for immediate assistance.

Main Phone Number: 303-238-7378

Main Fax Number: 303-205-1377

Electronic Payment/EFT Help
Phone: 303-205-8333
Report Tax Evasion, Fraud or Scams- Please call this number if you believe you are a victim of fraud or a scam.
Phone: 303-205-8262
Bankruptcy-Please contact this section only if you have an active case already filed in bankruptcy court.
Collections- The Collections Section can assist with payments, payment plans, wage/bank garnishments, judgments, liens, and third-party collection agencies.
Phone: 303-205-8291
Fax: 303-866-2037
Automated Collection Services, Inc. (ACSI)
Integral Recoveries, Inc. (IRI)
General Tax Questions
Phone: 303-238-7378
Email: - Please allow 3-4 business weeks for an email response for general tax inquiries. For a faster response, please call the general tax phone number or come in to one of the service center locations listed below. 
Compliance-The Compliance section can assist with outstanding tax debt for businesses.
Criminal Tax Investigations
Discovery-The Discovery Section can assist with tax adjustments and estimated returns based on third-party data. The Discovery Fraud Section can assist with taxpayer verification.
Phone: 303-205-8292
Fax: 303-866-3018
Excise Tax (cigarette and tobacco products tax and licensing, liquor excise tax, master settlement agreement, prepaid wireless fee, public utility administration fee)
Phone: 303-205-6848 or 303-205-6879

Fuel Tax (fuel excise, IFTA, aviation sales tax, exempt fuel, passenger mile tax)
Phone: 303-205-8205
Marijuana Tax
Sales Tax Changes
Field Audit
Phone: 303-692-7981
Tax Professionals Hotline
Phone: 303-232-2419

Sign Up for Tax News and Updates by Email

Subscribe to our free email subscription service to receive notifications when new tax information is available. With a subscription, you automatically receive updates without having to return to the website and check for changes. Email updates are a free service provided by CDOR. Your email address will only be used to deliver the information you've requested. 

Please select one (or more) from the list below and follow the sign up prompts. Return to this page to sign-up for more than one list.


Contact Us by Mail

Check the letter you received or your form for the correct mailing address first!  Be advised that sending without proper postage or via certified mail may delay the arrival of your mail, which may cause due dates to be missed.

Do not combine correspondence, payments or forms.  Each requires special handling and must be routed to the proper address. Please note these addresses and zip codes are exclusive to the Colorado Department of Revenue, so a   street address is not required.

       Correspondence - Letters & Protests via US Postal Service
               Colorado Department of Revenue
                Section or Employee Name and Room #
                PO Box 17087
                Denver CO 80217-0087
        Express Mail Delivery – DHL, FedEx, UPS, etc
                Colorado Department of Revenue
                 1375 Sherman Street
                 Denver CO 80203
        Bill Payments – Be Sure to Include Payment Voucher
                 Colorado Department of Revenue
                  Denver CO 80261-0004

Service Center Locations

When visiting our offices, it is important to note that you should bring your government-issued photo ID or driver license.  At this time, our office staff cannot accept cash or credit card payments.  All hand-delivered payments must be made with a check or money order, or to release a garnishment, a certified check. 

1375 Sherman St.
Denver CO 80203
Hours: Mon-Fri, 8am-5pm
Parking is limited to paid meters and lots, and is quite limited January – May during the legislative session.   
Colorado Springs 
2447 N. Union Blvd.
Colorado Springs CO 80909
Hours: Mon-Fri, 8am-5pm 
Fort Collins
3030 S. College Ave.
Ft. Collins CO  80525
Hours: Mon-Fri; 8am-5pm
Grand Junction
222 S. 6th St., 2nd Floor
Grand Junction CO  81501
Hours: Mon-Fri, 8am-5pm
827 W. 4th St., Suite A
Pueblo CO 81003
(Inside the DMV)
Hours: Mon-Fri, 8am-5pm

Citizen's Advocate

The Governor’s Office of Constituent Services ensures each State Department has a Citizen Advocate.  The Citizen Advocate is different from a Taxpayer Advocate in that they can assist in all divisions with the Department of Revenue including Enforcement, Lottery, Motor Vehicle and Taxation.  The advocate helps navigate concerns to Revenue management when normal methods for resolving issues or disputes have been ineffective.  Concerns are tracked to ensure a   prompt response.  Rules, regulation and statute can sometimes limit outcomes; however, the advocate will provide specifics.  We are restricted from providing any legal advice.  If this is your first attempt to resolve a problem, please use   one of our other contact methods listed above. The advocate will coordinate and facilitate a resolution with the appropriate division, generally within three working days.

ADA Accomodations

Relay Colorado is a free service for people with hearing or speech loss to communicate with standard telephone users.  Relay Colorado is available 24 hours per day, 365 days per year.
        Simply dial 711 to get connected
        TTY/TeleBraille 800-659-2656
        Voice 800-659-3656