Idaho Car Sales Tax Calculator
Idaho charges 6% Idaho sales and use tax on a used car purchase, verified September 15, 2026. Local taxes also apply; the range is not verified. A trade-in is deducted before tax. Private-party sales are taxed too, paid when you title the car.
Figures verified September 15, 2026; sources linked per row. Re-checked quarterly, next due December 15, 2026.
On a $20,000 used car, Idaho's tax, doc fee, title and registration come to $1,647: number 23 of 50 states, cheapest first. Every state compared
Taxable amount: $25,000. Tax only; dealer doc fees, title and registration are separate, and some states tax the doc fee as part of the price. The local figure is an estimate from the state's published range unless you entered your own rate.
The Idaho numbers, with sources
Each figure below was checked on September 15, 2026 against the page linked in the source column, and the wording the state uses is quoted so you can confirm it yourself.
| Item | Idaho | Source |
|---|---|---|
| State rate (Idaho sales and use tax) | 6% | tax.idaho.gov(state source)As published: “She doesn't owe Idaho tax because the amount paid Washington exceeds the amount she'd owe Idaho (6%, or $1,200).” |
| Local tax range | Yes, range not verified | tax.idaho.gov(state source)As published: “She doesn't owe Idaho tax because the amount paid Washington exceeds the amount she'd owe Idaho (6%, or $1,200).” |
| Trade-in credit | Yes, full credit | tax.idaho.gov(state source)As published: “You can accept merchandise as full or partial payment of a motor vehicle you sell. The amount allowed on the traded-in merchandise reduces the sales price.” |
| Dealer doc fee | No cap (typically $388) | itd.idaho.gov(state source)As published: “Any documentation fees charged must be clearly listed separately from other fees and identified to the customer as dealer document preparation fees that are subject to sales tax as part of the purchase price of the vehicle.” |
| Title fee | $14 to $32.75 | itd.idaho.gov(state source)As published: “The base title fee includes $14 plus county administrative fees, which vary by county ... County administrative fees range from $0.00 to $18.75” |
| Registration (by age) | $45 to $69 | itd.idaho.gov(state source)As published: “Passenger Vehicle (1 or 2 years old) $69.00 ... Passenger Vehicle (7 or more years old) $45.00” |
| Private-party sale taxed | Yes, paid when you title the car | tax.idaho.gov(state source)As published: “The county assessor (DMV) or the Idaho Transportation Department (ITD) will collect sales tax when you apply for an Idaho title.” |
- Local tax: Most of Idaho adds nothing to the 6% state rate. Its 23 resort cities each choose what their local option tax covers, and some include vehicle sales: Driggs charges 0.5% on all sales subject to state tax from January 1, 2026, while Ketchum excludes motor vehicles. The highest local rate on a vehicle was not verified.
- Trade-in: Dealer and retailer sales only; the guide states 'Trade-ins aren't allowed for private-party sales.'
- Doc fee: No cap. IDAPA 39.02.03.100.02.c only requires documentation fees to be listed separately and identified as dealer document preparation fees that are subject to sales tax. CarEdge's report of 93,200 verified quotes (July 2025 to September 2026) puts the average doc fee in Idaho at $388.
- Registration: Passenger vehicles: $69 at 1 or 2 years old, $57 at 3 to 6 years old, $45 at 7 or more years old; counties add administrative fees on top.
Next steps
- Out-the-door price calculator: adds the Idaho doc fee, title and registration to the tax for the full figure.
- Dealer doc fees by state and registration and title fees by state: see how Idaho compares.
- All states: the full sales tax table.
- Cheapest vehicle history reports: Carfax, AutoCheck and the NMVTIS-approved alternatives compared, prices checked.
Tax is fixed. The price is not.
Buying a specific car in Idaho? Run its VIN free for the specification and open recalls. From $2.99, see what it is worth at its mileage against cars for sale near your ZIP code. The $9.99 Negotiation Bundle adds an opening offer, a walk-away figure and the drive-away cost with Idaho tax and fees.
Idaho car tax questions
Does Idaho charge sales tax on a private-party car sale?
Yes. The buyer pays 6% use tax on the full price to the county assessor's DMV office or ITD when applying for the Idaho title; no trade-in allowance is given. Tax is on the bill-of-sale price; with no bill of sale, or one that looks low, the DMV taxes the NADA 'average trade-in price' for the same make, model, year, mileage and condition.
Does Idaho give a trade-in credit on car sales tax?
Yes. The value of your trade-in is deducted from the price before Idaho tax is calculated. Dealer and retailer sales only; the guide states 'Trade-ins aren't allowed for private-party sales.'
What is the dealer doc fee cap in Idaho?
Idaho sets no legal cap on dealer doc fees. Dealers typically charge $388. No cap. IDAPA 39.02.03.100.02.c only requires documentation fees to be listed separately and identified as dealer document preparation fees that are subject to sales tax. CarEdge's report of 93,200 verified quotes (July 2025 to September 2026) puts the average doc fee in Idaho at $388. If the dealer will not drop the fee, ask for the same amount off the price.
Do local sales taxes apply to car purchases in Idaho?
Yes. Most of Idaho adds nothing to the 6% state rate. Its 23 resort cities each choose what their local option tax covers, and some include vehicle sales: Driggs charges 0.5% on all sales subject to state tax from January 1, 2026, while Ketchum excludes motor vehicles. The highest local rate on a vehicle was not verified.
How much does a car title cost in Idaho?
$14 to $32.75 (flat). State title fee is $14; since July 1, 2023 each county may add its own title administrative fee (ITD notice https://itd.idaho.gov/wp-content/uploads/2023/06/DMV_title-fee.pdf: 'This is in addition to the current $14 title fee.'). amountMax is $14 plus the highest county fee listed ($18.75); Ada County's fee is $7, giving $21.
How much is annual car registration in Idaho?
$45 to $69 a year for a passenger car, by age. Passenger vehicles: $69 at 1 or 2 years old, $57 at 3 to 6 years old, $45 at 7 or more years old; counties add administrative fees on top.
Checking a specific car?