Agency Contact Information
| Agency main website |
Colorado Department of Revenue (DOR) |
Colorado Department of Labor and Employment |
| Tax Type/Format |
Withholding Account Number: XXXXXXXX (8 digits) |
UI Employer Account Number: XXXXXXXX (8 digits) |
| Colorado Unemployment Insurance Base Tax Rate |
- |
X.X% |
| Colorado Support Surcharge Rate |
- |
X.XX% |
| Colorado Solvency Surcharge Rate |
- |
X.XXX% |
| Agency Phone Number |
(303) 238-7378 |
(800) 480-8299 |
| Agency Address |
P.O. Box 17087Denver, CO 80217-0087 |
PO Box 8789Denver, CO 80201-8789 |
Supported Taxes
- CO Income Tax
- Income Withholding Tax Return (DR 1094)
- CO Unemployment Insurance Tax
- Unemployment Insurance Tax Report (UITR-1)
- CO Solvency Tax Surcharge
- CO Support Surcharge
- Colorado Family and Medical Leave Insurance (FAMLI)
- Various local income taxes
- Sheridan Occupational Privilege Tax
- Greenwood Village Occupational Privilege Tax
- Glendale Occupational Privilege Tax
- Denver Occupational Privilege Tax
- Aurora Occupational Privilege Tax
How to locate existing account numbers if you've already registered:
- Withholding Account Number: If you are already registered with the Department of Revenue, you can find your Colorado Account Number and Filing Frequency online or by contacting the CO Department of Revenue at (303)205-8333.
- Unemployment Account Number: If you already have a CO UI Employer Account Number, look this up online or find it on the Unemployment Insurance Rate Notice mailed by the CO Department of Labor and Employment. If you are unsure, contact the agency at (303)318-9100 or [email protected]. us.
- Aurora Occupational Privilege Tax (OPT): If you are already registered with the City of Aurora, you can retrieve your account number by contacting the agency at (303)739-7800.
- Denver Occupational Privilege Tax (OPT):If you are already registered with the City of Denver, you can find your Denver Account Number and Filing Frequency online or retrieve it by contacting the agency at (720)913-9400.
- Glendale Occupational Privilege Tax (OPT): If you are already registered with the City of Glendale, you can retrieve your account number by contacting the agency at (303)639-4706.
- **Greenwood Village Occupational Privilege Tax (OPT)**If you are already registered with the City of Greenwood Village, you can retrieve your account number by contacting the agency at (303)486-8299.
- Colorado Family and Medical Leave Insurance (FAMLI): If you have already registered for a FAMLI account number, you can call (866)263-2654 Monday through Friday from 7 a.m. to 6 p.m. Mountain Time.
How to register for new accounts
Colorado Account Number and Filing Frequency
Register online here. Your account will need the first 8 digits of your Colorado Account number, and your specific Filing Frequency.
Unemployment Insurance Account Number
By registering online here, you will receive your CO UI Employer Account Number.