Idaho car sales tax is 6% of the vehicle’s purchase price, whether you buy from a dealer or a private seller, and you pay it when you apply for a title at your county assessor’s motor vehicle office. The rate comes from Idaho Code § 63-3619. A $25,000 car means $1,500 in tax. Several exemptions exist for family sales, genuine gifts, certain military members, and new residents, but each one has specific paperwork and narrow eligibility.
What Reduces the Taxable Price
Two things lower the amount you’re taxed on: a dealer trade-in and a manufacturer rebate. Neither applies to a straight private-party sale.
If you trade in a vehicle at a dealership, Idaho lets you subtract the trade-in value from the purchase price before the 6% is calculated.1Legal Information Institute. Idaho Admin Code r 35.01.02.044 – Trade-Ins, Trade-Downs and Barter Buy a $30,000 car, trade in your old one for $10,000, and you pay tax on $20,000, a $600 savings. The trade-in has to be identified on the sales documents at the time of sale, and the dealer has to put it into resale inventory. This only works at dealerships.
Manufacturer rebates on motor vehicles reduce the taxable price as long as the dealer’s invoice shows the rebate as a price reduction or down payment.2Legal Information Institute. Idaho Admin Code r 35.01.02.051 – Discounts, Coupons, Rebates, and Gift Certificates A $3,000 rebate on a $28,000 sticker price leaves you owing tax on $25,000. The favorable treatment is specific to motor vehicles; rebates on trailers and off-highway equipment don’t qualify.
Dealer Sales vs. Private Party Sales
Dealers collect the 6% at the point of sale as part of your paperwork. Private sellers don’t. In a private sale, no one collects tax at the transaction itself; you pay the county assessor’s motor vehicle office when you go in to put the title in your name.3Idaho State Tax Commission. Types of Sales – Motor Vehicles – Private and Nondealer
The tax is based on what you actually paid, documented by the bill of sale. Both buyer and seller sign the bill of sale, and the seller signs the title to release their interest. Confirm the vehicle is already titled in the seller’s name before you hand over money.3Idaho State Tax Commission. Types of Sales – Motor Vehicles – Private and Nondealer
Do not understate the price on the bill of sale to shrink the tax. Listing a false selling price is a felony under Idaho law.4Idaho State Legislature. Idaho Code 49-518 – Altering or Forging
Family Sale Exemption
Sales between close family members are exempt from the 6%, but the qualifying relationships are narrow. Only parent and child, grandparent and grandchild, and brother and sister count.5Idaho State Legislature. Idaho Code 63-3622K – Occasional Sales Aunts, uncles, cousins, and in-laws are not on the list. If the vehicle is community property, it can be sold to a qualifying relative of either spouse.6Idaho State Tax Commission. Form ST-133 – Sales Tax Exemption Certificate Family or American Indian Sales
There is a catch worth checking before you plan on the exemption: the seller must have already paid sales or use tax when they originally acquired the vehicle. If the seller got the car tax-free, the family exemption doesn’t carry forward and the buyer owes the full 6%.5Idaho State Legislature. Idaho Code 63-3622K – Occasional Sales The exemption also covers motor vehicles only. Boats, ATVs, UTVs, snowmobiles, off-road motorcycles, and trailers are not included.
Both parties complete and sign Form ST-133 and submit it to the county assessor’s office with the title transfer.6Idaho State Tax Commission. Form ST-133 – Sales Tax Exemption Certificate Family or American Indian Sales
Gift Transfers
A true gift can be transferred without sales tax, but Idaho sets conditions designed to catch disguised sales. All three must hold:7Legal Information Institute. Idaho Admin Code r 35.01.02.107 – Vehicles and Vessels
- No money, services, or other consideration changes hands at any time
- The recipient doesn’t assume any debt tied to the vehicle
- The relationship between donor and recipient gives a reasonable basis for a gift
Both parties complete and sign Form ST-133GT (Use Tax Exemption Certificate — Gift Transfer Affidavit) and submit it with the title. If the donor can’t sign in person, they can provide a signed letter stating the vehicle is a gift, or mark the title itself as a gift and sign it.7Legal Information Institute. Idaho Admin Code r 35.01.02.107 – Vehicles and Vessels
Military and Nonresident Situations
Active-duty military stationed in Idaho whose home of record is another state can buy an Idaho vehicle without paying the 6%, but only with orders to report to a duty station outside Idaho within 90 days. If the vehicle stays in Idaho longer than 90 days, the full tax applies.8Idaho State Tax Commission. Military Bring a copy of your orders at the time of sale and complete Form ST-104NR.
Nonresidents don’t owe Idaho use tax on a vehicle registered in their home state so long as they don’t use it in Idaho more than 90 days in any 12-month period and no buyer on the title is an Idaho resident.9Idaho State Legislature. Idaho Code 63-3621 – Imposition and Rate of Use Tax Full-time nonresident students enrolled at an accredited Idaho institution are exempt from use tax on their vehicles while enrolled.
Buying Out of State or Moving to Idaho
Buy a vehicle in another state and bring it in, and you owe Idaho’s 6% use tax when you register and title it.9Idaho State Legislature. Idaho Code 63-3621 – Imposition and Rate of Use Tax Sales tax you already paid to the other state is credited against what you owe Idaho. Paid 4% elsewhere? You owe Idaho 2%. Paid 6% or more? You owe nothing additional.
Moving to Idaho with a vehicle you already own usually means no use tax, as long as you acquired it while living elsewhere and used it primarily outside Idaho.7Legal Information Institute. Idaho Admin Code r 35.01.02.107 – Vehicles and Vessels A registration or title from your previous state issued more than three months before your move is sufficient proof. If you bought it less than three months before relocating, Idaho presumes it was acquired for use in the state and you may owe the tax.
If you’re coming from a state without a general sales tax, like Oregon or Montana, complete Form ST-102 (Use Tax Exemption Certificate — New Resident) and submit it to the county assessor when you transfer the title.7Legal Information Institute. Idaho Admin Code r 35.01.02.107 – Vehicles and Vessels
When and Where to Pay
You have 30 days from the date of transfer to apply for a title and pay any tax owed. Miss the deadline and a $20 late-filing penalty is added automatically.10Idaho Transportation Department. Vehicle Titles For private sales, you handle it at your county assessor’s motor vehicle office. For out-of-state dealer purchases, the dealer may file the title application with the Idaho Transportation Department for you, but the 30-day clock runs either way, so if they don’t, you need to file at the county office yourself.