Wyoming Used Car Sales Tax: County Rates, 65-Day Deadline, Exemptions

Wyoming charges sales or use tax on a used car at the combined rate for the county where you live, which the state's Excise Tax Division says is generally 4% to 8% (a 4% state rate plus any voter-approved local pennies). You pay it to your county treasurer, not the seller, and you have 65 days from the sale to do it before interest and a civil fee kick in. Same rule for a dealer sale or a neighbor's old truck. As of Oct 20, 2026, the county pages I checked ranged from 4% in Park County to 7% in Teton County.

I read the Excise Tax Division's FAQ, the current Title 39 statute file from the Wyoming Legislature, the Department of Revenue rule on vehicle sales and use tax, and the treasurer pages for Fremont, Park, Sheridan and Teton counties on Oct 20, 2026. The worked examples below are my own arithmetic using those posted rates, not the state's.

How the tax works

Under W.S. 39-15-107, motor vehicle dealers don't collect the tax. The county treasurer collects it before the car's first registration, using the rate for the county of your principal residence, which the statute ties to the address on your driver's license. The Revenue rule says the same: the rate follows where the buyer lives, not where the car was bought. A Jackson resident who buys a truck in Riverton pays Teton's rate.

The tax base, per Teton County's page, is the price less the gross trade-in allowance, and it includes transportation costs, documentation fees and any add-ons. The statute only excludes the trade-in when it's part of the same transaction. So, two quick examples of my own:

• A $12,000 private-party car in Fremont County at 5%: about $600, figured from a bill of sale. Fremont says it uses the bill of sale for dealer and private sales alike.
• A $12,000 dealer car in Teton County at 7%, with a $3,000 trade-in taken in the same deal: $9,000 taxable, so about $630, plus 7% of any doc fee.

Look up the rate for your own county before you budget. Rates change when voters approve or drop a local option tax, and the four counties I checked weren't the same.

The 65-day deadline and late charges

W.S. 39-15-108 starts interest at 1% per month (or part of a month) from the 65th day after the sale. A $25 civil fee applies from day 65 through day 75; if everything still isn't paid by day 75, the fee becomes $25 or 10% of the tax, whichever is greater. Park County's treasurer page describes the jump to 10% as starting on day 66, so the county wording and the statute don't quite match. Either way, on a $600 tax bill you'd be looking at $60 plus interest once you're well past the deadline. Pay early and skip the argument.

For a car you bring into the state, the 65 days can run from the day it entered Wyoming instead, if you give the treasurer an affidavit and proof of that date. And the statute gives you credit for sales tax you legally paid to another state, up to what Wyoming's use tax would be.

Exemptions worth knowing

• Family transfers: W.S. 39-15-105 exempts a sale or gift between immediate family members (parent, child, spouse, sibling, stepparent, stepchild, stepsibling, grandparent or grandchild) as long as the seller or giver paid the tax.
• Gifts from anyone else: the statute taxes the person receiving it. Park County says that without proof the giver paid tax, it'll charge tax on fair market value.
• Nonresidents: a buyer who isn't a Wyoming resident and takes the car out of the state within 30 days can be exempt by signing a declaration under penalty of perjury.
• New residents: the treasurer doesn't collect tax on a car already registered in another state by the same nonresident owner. Sheridan County adds that retirees moving in have up to 120 days to register.

Registration fees on top

Tax is only part of the bill. Sheridan County's page shows the county registration fee formula: factory price times a year-of-service rate times 0.03, with rates stepping down from 60% in the first year to 15% from the sixth year on. Its own example is a $48,000 factory price in year three, which comes to $576. A 15-year-old car with a $25,000 factory price would be $25,000 x 15% x 0.03, or $112.50 by my math, plus the $30 state fee for a passenger car. In Sheridan you title at the County Clerk first, then register with the Treasurer. Our Wyoming title transfer guide walks through the paperwork, and the used car sales tax overview compares Wyoming with other states.

Park County also notes a private-party buyer can drive for 45 days on a notarized bill of sale or signed-over title, versus 60 days for a dealer purchase. That's still inside the 65-day tax window.

Check the car before you pay anything

Once you've paid the tax and titled the car, a hidden flood or salvage brand is your problem. Run the VIN through NMVTIS and get a CARFAX or AutoCheck report, and read our Wyoming salvage and rebuilt title rules if the seller mentions any past damage.

CarVins is a licensed reseller of CARFAX and AutoCheck reports with no affiliation to either company or to the State of Wyoming. Our late October 2026 prices were around $5.50 a report as a guest and $4.50 as a member, or about $6.75 for both, against roughly $39.99 to $44.99 retail. Confirm the figure at checkout; that's the one that counts.

Sources

• Wyoming Excise Tax Division: FAQs
• Wyoming Statutes Title 39 (W.S. 39-15-105, -107, -108)
• 011-2 Wyo. Code R. Sec. 2-11, vehicle sales and use tax rule (via Cornell LII)
• Fremont County Treasurer, Teton County, Park County and Sheridan County pages, read Oct. 20, 2026