Idaho Vehicle Sales Tax Calculator

Idaho charges 6% sales tax on a vehicle, and it’s the same everywhere in the state. A trade-in lowers the taxable price when it’s part of the same deal. Registration costs $45 to $69 a year, depending on how old the vehicle is. Your county adds its own title and handling fees.

Use this Idaho vehicle sales tax calculator to estimate the tax, title and registration on a new or used vehicle. Below, you’ll find the rules for trade-ins, rebates, private sales and family transfers, plus three worked examples.

Checked against the Idaho State Tax Commission, the Idaho Transportation Department and the Idaho Code on October 22, 2026. This is an independent estimate. Your county assessor’s office sets the final amount.

Idaho Car Tax and Fees at a Glance

How Idaho Vehicle Sales Tax Is Calculated

Sales tax = (price + documentation fee − rebate − qualifying trade-in) × 6%

Idaho’s rate is 6%. It doesn’t change by city or county, so two buyers with the same vehicle pay the same tax. That makes the estimate simpler than in states with local add-ons. Kentucky charges a 6% motor vehicle usage tax too, and Minnesota charges 6.875%.

If you buy from a dealer, the dealer collects the tax. If you buy from a private seller, you owe use tax when you apply for the title, unless an exemption applies.

Does a trade-in lower the tax in Idaho?

Yes, but the trade must pass three tests. The sales papers must list both the vehicle you’re buying and the one you’re trading in. They must be signed no later than the time of sale. And the trade-in and purchase must happen as one transaction.

Trade-ins aren’t allowed on private sales. If you sell your old car to a neighbor and buy another from someone else, you can’t subtract the first sale.

Do rebates lower the tax in Idaho?

Sometimes. A manufacturer’s rebate on a motor vehicle lowers the taxable price if you use it as a reduction in price or a down payment, and the seller lists it on the invoice. Rebates on trailers and off-highway vehicles don’t lower the tax.

Louisiana is a useful comparison. Louisiana subtracts manufacturer rebates from the price without a condition like this one.

Are dealer fees taxed in Idaho?

Yes. A dealer’s documentation fee is part of the taxable price, because it pays for a service tied to the sale. Government title and registration fees aren’t taxed.

How Much Is Car Sales Tax in Idaho?

Example 1: New SUV from a dealer in Canyon County

Assumptions: $34,000 price, $400 documentation fee, a $1,000 manufacturer rebate shown on the invoice as a price cut, $9,000 trade-in in the same deal, first-year registration, gas engine.

Example 2: Used car from a private seller in Kootenai County

Assumptions: $14,000 price shown on the bill of sale, a five-year-old car, no family relationship, no trade-in.

Example 3: New electric car from a dealer in Bonneville County

Assumptions: $45,000 price, no trade-in, first-year registration, annual EV fee.

Ada County buyers pay an extra Ada County Highway District fee of $24 to $40 on registration. It isn’t in these examples.

Idaho Registration Fees by Vehicle Age

Idaho doesn’t charge by weight or by value for a passenger vehicle. It charges by age. The newer the vehicle, the more you pay. The fee drops twice as the vehicle gets older.

Your county adds an administrative fee and mailing fee, and the state adds a $1.25 EMS fee and a $3.00 State Police fee. A set of new plates, if you need them, costs $3.75 per plate plus postage. Personalized plates cost $25 to start and $15 a year after that.

You can renew online up to a year before or after the expiration date. Renewing early doesn’t change the new expiration date.

Idaho Title Fee and County Fees

The state title fee is $14. Each county adds its own title administrative fee, so the total ranges from $14 to $32.75. Registration also carries a county administrative fee of $3 to $14.

A vehicle must be titled before it can be registered. In practice, you apply for both at your county assessor’s motor vehicle office. Check the ITD county table for your county, since amounts change. New residents must register and title within 90 days of moving.

Idaho Electric Vehicle and Plug-In Hybrid Fees

Idaho Code 49-457 adds an electric vehicle fee of $140 to your registration each year. Plug-in hybrids pay $75 a year. Regular hybrids and gas cars don’t pay a fee. Neighborhood electric vehicles are exempt.

These fees are on top of the age-based registration. A new electric car in its first two years costs $69 plus $140, or $209, before county fees. Kentucky’s electric vehicle fee is $126 a year, so Idaho’s is higher.

What a New Car Really Costs at Registration in Idaho

The tax is the big number. The county fees are small but easy to forget. The graphic below shows Example 1 line by line.

Private Sales, Family Transfers and Out-of-State Purchases

Do I pay tax on a private car sale in Idaho?

Yes. You pay use tax when you apply for the title, based on the price on your bill of sale. If you have no bill of sale, the Tax Commission uses the average trade-in price in the NADA guide for the same year, make, model, mileage and condition.

Is there a family exemption in Idaho?

Yes. A sale between parent and child, grandparent and grandchild, or brothers and sisters is exempt. You’re related by blood or formal adoption. Both of you must sign Form ST-133. The exemption covers motor vehicles only.

A true gift isn’t taxed either. You can’t pay money, goods or services, and you can’t take over the giver’s loan. Use Form ST-133GT. A vehicle you inherit isn’t taxed if you have a court order or an affidavit of inheritance. Spouses aren’t named in the family exemption. Alabama also exempts transfers between close family members, with its own list.

What if I buy a car in another state?

Idaho gives you credit for general sales tax you properly paid to another state. If that state’s tax was lower than Idaho’s 6%, you owe the difference. If it was 6% or more, you owe nothing. Tax paid to another country doesn’t count.

New residents, nonresidents and the military

A new resident owes no tax on a personal vehicle if they bought it more than 90 days before moving to Idaho and used it mainly outside the state. Active-duty military members who are temporarily assigned to Idaho have the same 90-day rule, with Form ST-102NM.

A nonresident who buys a vehicle and takes it out of Idaho right away can claim an exemption with Form ST-104NR. The vehicle can’t be used in Idaho for more than 90 days in 12 months.

See also: Wyoming: a 4% state sales tax plus local taxes.

See also: Pennsylvania: a 6% state tax plus local add-ons.

See also: Nevada: dealer sales tax and a yearly governmental services tax.
See also: Oregon: no sales tax, but a 0.5% vehicle privilege tax.

See also: Montana: no sales tax; a registration fee by vehicle age.

How to Calculate Idaho Tax, Title and License Costs by Hand

• Start with the price. Add the dealer’s documentation fee.
• Subtract a manufacturer rebate only if it’s shown on the invoice as a price cut or down payment.
• Subtract your trade-in if it qualifies (same transaction, listed on the papers, not a private sale).
• Multiply by 6%. For a private sale, use the bill-of-sale price. Subtract tax you paid to another state.
• Add the title fee: $14 plus your county’s fee.
• Add registration by age: $69, $57 or $45.
• Add your county registration fee ($3 to $14), plus $1.25 and $3.00 in state fees.
• Add $140 for an electric vehicle or $75 for a plug-in hybrid.

Your county assessor’s office can confirm the final amount.

What This Estimate Includes

• 6% sales or use tax with trade-in, rebate and doc-fee rules
• $14 state title fee and county title fees
• Age-based registration and county registration fees
• EMS and State Police fees
• Electric and plug-in hybrid fees

What This Estimate Does Not Include

• Ada County Highway District fee
• Personalized or specialty plate fees
• Local option taxes where a community has one
• Insurance, loan interest and optional products
• Late fees and penalties

Common Mistakes to Avoid

• Subtracting a trade-in on a private sale. Idaho doesn’t allow it.
• Skipping the rebate condition. The rebate must be listed on the invoice as a price cut or down payment.
• Forgetting the doc fee is taxed.
• Using the 3-to-6-year registration fee on a new car. A vehicle 1 to 2 years old pays $69.
• Missing the county fees. Title and registration costs differ by county.
• Assuming spouses are covered by the family exemption. It lists parent, child, grandparent, grandchild and sibling.
• Skipping the paperwork. Family and gift exemptions need signed forms.
• Waiting past 90 days as a new resident.

Frequently Asked Questions

What is the sales tax on a car in Idaho?

It’s 6%, with no city or county add-on.

Does an Idaho vehicle sales tax calculator subtract a trade-in?

Yes, if the trade-in qualifies. It must be listed on the sales papers and happen in the same transaction. It isn’t allowed on private sales.

How much is sales tax on a $30,000 car in Idaho?

It’s $1,800 on a taxable price of $30,000.

How much does it cost to register a car in Idaho?

It’s $69 for a vehicle 1 to 2 years old, $57 for 3 to 6 years old and $45 for 7 or more years old, plus county, EMS and State Police fees.

How much is the Idaho title fee?

The state fee is $14. Counties add up to $18.75, so most buyers pay $14 to $24.

How much is the Idaho electric vehicle fee?

It’s $140 a year. Plug-in hybrids pay $75 a year.

Are rebates taxed in Idaho?

A manufacturer rebate on a motor vehicle lowers the taxable price when it’s shown on the invoice as a price cut or down payment. Otherwise, it’s taxed.

Is there a family exemption for cars in Idaho?

Yes, for parent and child, grandparent and grandchild, and siblings. Both of you sign Form ST-133.

Do I get credit for sales tax paid in another state?

Yes. You get credit up to Idaho’s 6% rate and owe only the difference.

How long do new residents have to register in Idaho?

You must register and title the vehicle within 90 days of moving.

Official Sources

• Idaho State Tax Commission: Sales and Use Tax Guide for Vehicle Transactions
• Idaho Transportation Department: Vehicle Registrations (county fees)
• Idaho Transportation Department: Fact Sheet, Registering Vehicles in Idaho
• Idaho Code 49-457: Electric vehicle fee

This page is an independent estimate tool and guide. It isn’t affiliated with the Idaho State Tax Commission, the Idaho Transportation Department or any county assessor. Rates and fees can change, so confirm your total before you pay.