South Dakota Used Car Tax: 4% Excise, Bill of Sale, Exemptions and 45 Days

South Dakota doesn't charge sales tax on a used car. It charges a 4% motor vehicle excise tax instead, on the purchase price, paid to the county treasurer when you title the car. In a private sale the price on the state's approved bill of sale sets the tax, and if you don't turn one in, the treasurer uses a dealer guide's retail value. Transfers with no money between spouses, parents and children, or siblings are exempt, and so is a car 11 or more model years old sold for $2,500 or less. You have 45 days from the purchase date before interest starts.

I read South Dakota Codified Law chapter 32-5B and the Department of Revenue's motor vehicle fee pages and government FAQ on Oct 19, 2026, and everything below is as of that date. For the signing and paperwork side, our South Dakota private-sale title transfer guide covers it.

The 4% and what counts as the price

Section 32-5B-1 sets the excise tax at four percent of the purchase price of any motor vehicle bought for use on South Dakota roads that has to be registered, and says it's charged in place of the state's sales and use taxes. Failing to pay the full amount is a Class 1 misdemeanor. Section 32-5B-4 defines the price. For a used car from a licensed dealer, it's the total consideration minus the trade-in allowance. For a car sold by anyone else, it's also the total consideration minus any trade-in, but the buyer and seller have to submit a bill of sale on the form the state approves. Skip the bill of sale and the tax is figured on the retail value in a nationally recognized dealers' guide, and the trade-in is valued at guide retail too.

So the bill of sale matters more here than in many states. A $4,000 private sale with the proper form is $160 in tax. Without it, the treasurer looks the car up, and if the guide says $7,000 retail you'd owe $280. That example is our own math, not a state figure.

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Field guides, red flags, and the occasional discount.

Gifts and family transfers

A gift isn't automatically tax-free. Under 32-5B-4, a used car acquired by gift or for nominal money is taxed on its dealer-guide retail value. Section 32-5B-2 then exempts a long list of transfers, including these:

Transfers without consideration between spouses, between a parent and child, and between siblings. Section 32-5B-18 says siblings include brothers and sisters by blood, marriage or adoption.
Vehicles inherited from or left by a person who died.
A car titled jointly that goes, without payment, to one or more of the co-owners.
Transfers from a trustor to a trustee, or from a trustee to a beneficiary.
Any vehicle 11 or more model years old sold or transferred for $2,500 or less before trade-in.

That last one is worth knowing if you shop cheap older cars. The pages I read don't spell out how the county counts model years, so on a borderline car, ask the treasurer before you assume it qualifies. A grandparent or an aunt giving you a car doesn't fit the family list, so that gift would be taxed on guide value unless another exemption applies.

Deadlines, interest and penalties

The DOR's FAQ says that since July 1, 2015, owners have 45 days from the purchase date to apply for title and registration, and the state has no provision for extensions. Fees are figured from the purchase date, not the day you show up. The DOR's title and fees page and its FAQ say interest is 1% or $5, whichever is greater, for the first month and 1% a month after that, on applications made after 45 days. After 60 days, a one-time penalty of 10% of the tax or $10, whichever is greater, is added. A late title fee of $1 a week past the 45-day grace period also applies, capped at $50.

One discrepancy I found: the DOR's separate cars, trucks and vans page lists the interest at 1-1/4% a month instead of 1%. If you're past day 45, ask your county treasurer which rate they'll apply. Better yet, don't be past day 45.

For fees, the DOR lists a $10 title fee, $10 lien notation fee and a $2 technology fee that started July 1, 2025. A private seller is supposed to give you a free 45-day seller's permit so you can drive the car before it's registered.

Out-of-state taxes, new residents and nonresidents

Section 32-5B-11 says no South Dakota tax is owed if the applicant already paid a sales, use or excise tax on the vehicle to another state. The FAQ explains how that works for people moving in: if your old state's rate was 4% or higher, you pay nothing more; if it was lower or zero, you pay the difference up to 4%. New residents have 90 days from arrival to title and license their vehicles.

South Dakota also has a $100 administrative fee for people who title a vehicle there without a South Dakota driver's license or ID card or a physical South Dakota address; P.O. boxes and mail forwarding addresses don't count. The DOR doesn't say why the fee exists, but it does show the state titles vehicles for people with no South Dakota license or address. Whether doing that is allowed for you depends on your home state's registration and residency rules, which this page doesn't cover. Check them before you try it.

What the title won't tell you

South Dakota used to require a damage disclosure statement on sales. The DOR's FAQ says it's no longer mandated as of July 1, 2015, though it still appears on titles issued before then. That leaves you to find damage history yourself, hail damage included. Our posts on South Dakota hail salvage titles and salvage and rebuilt title rules explain the brands. Check the title history on NMVTIS, then a CARFAX or AutoCheck report for insurance claims and odometer readings. We're a licensed reseller of both and not affiliated with CARFAX, AutoCheck or Experian. As of mid October 2026, reports were about $5.50 for guests and $4.50 for members, or about $6.75 for the pair, versus roughly $39.99 to $44.99 retail; check the total at checkout before you buy. For how other states tax used cars, see our used car sales tax overview.