Verify an Exempt Certificate
The Department of Revenue offers a 24-hour, automated service for those wanting to verify a Colorado sales tax license or sales tax exemption certificate for a specific business or organization. This License Verification Service determines whether a Colorado sales tax license or state sales tax exemption certificate is valid. You must know the sales tax account number or exemption certificate number as assigned by the Department of Revenue.
You may also use this service by calling (303) 238-FAST (3278).