Connecticut Used Car Sales Tax: 6.35%, 7.75% Over $50,000, NADA Value and CERT-106

Connecticut charges 6.35% sales or use tax on a used car, or 7.75% if the vehicle costs more than $50,000. Buy from a dealer and it's figured on the price after your trade-in. Buy from a private seller and the DMV taxes the higher of what you paid or the car's NADA average trade-in value, so a lowball bill of sale doesn't lower your bill. If you really did pay less than book, the state will refund the difference, but you have to ask for it on Form CERT-106 within three years.

I read the Connecticut DMV's page on sales tax for registrations, the Department of Revenue Services page on CERT-106, the DRS use tax page and the DMV's ownership transfer page on Oct 19, 2026. Everything below is what those pages say, with my own arithmetic where noted.

Dealer vs. private seller

• Licensed dealer: tax is on the purchase price, and the DMV says it allows full trade-in credit.
• Private seller: the DMV taxes passenger cars and light trucks at 6.35% (7.75% over $50,000) on the NADA average trade-in value or the bill of sale price, whichever is higher. The purchase price goes on the Application for Registration and Title, Form H-13B.

Try the math with made-up numbers. You pay a private seller $7,000 for a car whose NADA average trade-in is $9,500. Tax at 6.35% on $9,500 is $603.25, where tax on your price would have been $444.50. DRS says the book figure comes from the N.A.D.A. Official Used Car Guide, Eastern Edition, for the month you bought it. Your car's book value will differ.

The 7.75% rate is real money on the expensive end. DRS describes it as applying to "most motor vehicles with a sales price of more than $50,000." On a $55,000 car that's $4,262.50 versus $3,492.50 at 6.35%. On a private sale near the line, ask the DMV whether the $50,000 test uses your price or the book value, since neither page spells that out.

Getting money back with CERT-106

If the car was worth less than book because it needed work, DRS will refund the overpayment once you prove the real price. File CERT-106 through myconneCT within three years of paying the tax at the DMV. DRS wants a purchaser's declaration, the bill of sale, the DMV receipt showing tax paid, a cancelled check or bank statement showing what you paid the seller, and an explanation with evidence like a dated photo, repair bill or appraisal. Take those photos the day you buy the car. It's much harder to prove condition a year later.

Family, gifts and loan takeovers

No tax is due on a transfer or sale between immediate family, which the DMV defines as mother, father, sister, brother, son, daughter, husband, wife or civil union partner. The car has to have been registered in the family member's name for at least 60 days and taxed on its last sale, and the exemption is blocked if tax is delinquent on the car or the registration is suspended. Grandparents and in-laws aren't on the list.

A true gift is also tax-free, with a Motor Vehicle or Vessel Gift Declaration (AU-463) signed by the giver. The giver can't get anything back, including someone taking over the loan, and the DMV notes the giver may owe Connecticut gift tax. If you do take over a loan, the DMV says the taxable price is what you gave the seller plus the loan you assumed. Swapping cars with a friend? Both of you can owe tax based on book value.

Military, new residents and out-of-state purchases

• Military: Connecticut residents in the armed forces pay the normal rates. Nonresident service members on full-time active duty in Connecticut can buy from a licensed Connecticut dealer at a reduced 4.5% with DRS Form CERT-135.
• New residents: no sales tax if the car was registered in the same name in another state for at least 30 days before you moved.
• Bought out of state: you get credit for tax paid elsewhere with an invoice and tax receipt, and you pay the difference if the other state charged less.

Then comes property tax

Connecticut cars also carry a local property tax from your town, registered or not. The DMV says assessments are based on 70% of average retail value, the assessment date is Oct. 1, and unpaid car tax will block you from registering or renewing until it's cleared. Budget for it. It's a separate bill from the sales tax and it shows up every year. Our Connecticut private-sale title transfer guide covers the title steps.

Check the history before the DMV visit

A private sale taxed on book value is a bad place to discover the car was a total loss in another state. Connecticut's brands are covered in our Connecticut salvage and rebuilt title rules. Run the VIN on NMVTIS, then a CARFAX report or AutoCheck, and keep the report with your CERT-106 evidence if it shows damage. For other states, see our used car sales tax overview.

CarVins resells CARFAX and AutoCheck reports under license and is not affiliated with CARFAX, AutoCheck or Experian. As of mid October 2026, a guest report was around $5.50, a member report around $4.50, and the CARFAX plus AutoCheck pair around $6.75, against about $39.99 to $44.99 at retail. Prices change now and then, so treat the checkout total as the real one.

Sources

• CT DMV: Sales tax on first time vehicle registrations (read Oct. 19, 2026)
• CT DRS: CERT-106, refund of use tax on a vehicle bought from a non-dealer
• CT DRS: Individual use tax information
• CT DMV: Transfer vehicle ownership