Colorado › Boulder County
Boulder County car sales tax: 5.335% to 9.335%
The rate in Boulder County
- Vehicle sales tax in Boulder County is not a single number — it runs from 5.335% to 9.335% depending on which city you register in. Most of the county is at 5.335%.
- That is above the 2.9% most Colorado counties charge — about $852.25 more tax on a $35,000 car than the typical county in the state.
- No other county in Colorado charges this rate — Boulder sits at number 12 of 64 by combined rate.
Where the rate changes inside Boulder County
- 9.335% — Lyons (dealer inside your area).
- 9.195% — Boulder.
- 9.115% — Superior.
- 9.11% — Louisville.
- 9.105% — Lafayette.
- 8.865% — Longmont.
- 8.835% — Erie.
- 8.335% — Lyons, Nederland.
- 7.335% — Ward (unincorporated) (dealer inside your area).
- 5.335% — Boulder (unincorporated), Longmont (unincorporated), Allenspark (unincorporated), Eldorado Springs (unincorporated), Hygiene (unincorporated), Jamestown, Lafayette (unincorporated), Lyons (unincorporated) and 4 more.
- This is why a county-wide figure is not enough here: two addresses in Boulder County can carry different tax on the same car, and in 15 of its ZIP codes the boundary runs through the middle so the ZIP alone cannot settle it. The calculator asks you which side you are on.
What a $35,000 car actually costs in Boulder County
- Sales tax (9.195% — Boulder, Boulder County) — $3,276.73
- Doc fee (typical) — $636.00
- Title fee — $7.20
- Specific ownership tax — $3.00
- Registration fee (by weight) (est.) — $9.00
- Vehicle age fee — $7.00
- Road safety surcharge (est.) — $19.30
- Bridge safety surcharge (est.) — $18.00
- County clerk hire fee — $4.00
- Emergency medical services fee — $2.00
- Peace officer training fee — $1.00
- Air account and county emissions-program fees — $1.20
- Emissions program area fee (est.) — $1.50
- Motorist insurance database fees (est.) — $0.60
- License plates and tabs (est.) — $8.31
- Out the door — $38,994.84 on a $35,000 used car, before any down payment or financing.
Charges that apply only in Boulder County
- Emissions program area fee — $1.50. An extra $1.50 in the Denver-area and Front Range emissions program area. Only part of Adams, Arapahoe, Larimer and Weld counties is in the area, so this may not apply to your address. (C.R.S. 42-3-304(18)(b); DMV Vehicle Taxes and Fees page)
- These apply in Boulder County specifically and not across the rest of Colorado, so a statewide estimate will miss them.
ZIP codes in Boulder County
- 80025, 80026, 80027, 80301, 80302, 80303, 80304, 80305, 80306, 80307, 80308, 80309, 80310, 80314, 80455, 80466, 80471, 80481, 80501, 80502, 80503, 80504, 80510, 80516, 80533, 80540, 80544.
- Any of these resolves to Boulder County in the calculator, at whichever of the county's rates applies to that ZIP.
Boulder County against nearby counties
- El Paso County is 5.13% — $71.75 LESS tax on a $35,000 car than Boulder County.
- Mesa County is 5.27% — $22.75 LESS tax on a $35,000 car than Boulder County.
- Fremont County is 5.4% — $22.75 MORE tax on a $35,000 car than Boulder County.
- Alamosa County is 5.9% — $197.75 MORE tax on a $35,000 car than Boulder County.
- This follows where you REGISTER, not where the dealer is, so a lower rate nearby only helps if you actually live there. It is not something you can choose at the dealership.
Run your own numbers
Common questions
Why is the car sales tax different in parts of Boulder County?
Cities inside the county can levy their own rate on top of the county and state rate, so the combined figure changes at the city line. In Boulder County it ranges from 5.335% to 9.335%.
Are there extra car fees in Boulder County?
Yes — 1 charge applies here that does not apply statewide. The amounts and the statute behind each are listed above.
What is the car sales tax rate in Boulder County?
It ranges from 5.335% to 9.335% depending on the city; most of the county is 5.335%.
How much is tax and fees on a $35,000 car in Boulder County?
About $3,994.84 on top of the price, bringing it to roughly $38,994.84 out the door. The breakdown is above.
Elsewhere in Colorado
Fremont County
5.4% on a vehicle purchase
Mesa County
5.27% on a vehicle purchase
El Paso County
5.13% on a vehicle purchase
Conejos County
4.9% on a vehicle purchase
Crowley County
4.9% on a vehicle purchase
Full Colorado out-the-door guide
Rates, doc fees, registration and title for the whole state
How Colorado sales tax works
What sits in the taxable amount, and how the rate is sourced