Bill of Sale Aug 13, 2026
Selling or buying a car in Connecticut? You're going to need a piece of paper that most people ignore until the last minute: the bill of sale. It sounds like a small thing. It isn't.
Without it, the Connecticut Department of Motor Vehicles (DMV) won't let the buyer register the car or get a title in their name. That means no license plates, and legally, no driving it home.
This guide walks you through everything you need to know about the Connecticut bill of sale — what it is, what it must include, how sales tax works, and how to avoid the mistakes that slow buyers and sellers down.
At KarKiosk, we help private sellers list, price, and sell their cars directly to buyers — no dealer markup, no hassle. Understanding the paperwork is a big part of getting that sale done right.
What Is a Connecticut Bill of Sale?
A bill of sale is a signed document that records the sale of a vehicle between two parties. It proves that ownership changed hands, at what price, and on what date.
In Connecticut, this isn't optional. The Connecticut DMV requires a bill of sale as part of the registration and title transfer process for privately sold vehicles.
Connecticut's official form is called Form H-31. You can either:
Use the state's printable H-31 form, or
Write your own bill of sale, as long as it includes the same required information
Either version works at the DMV, as long as nothing important is missing.
Why the Bill of Sale Matters So Much
Here's the thing people miss: a bill of sale is not the same as a title.
The title proves who legally owns the car. The bill of sale proves the transaction — the price, the date, the parties involved. Connecticut's DMV is clear that a bill of sale does not replace a title transfer; you need both documents to complete a legal sale.
For sellers, the bill of sale also protects you. If a buyer never registers the car or it gets abandoned somewhere, your signed bill of sale is proof you're no longer the legal owner of that headache.
For buyers, it's the document the DMV uses to calculate the sales tax you owe — which we'll get to shortly.
What Information Goes on a Connecticut Bill of Sale
Whether you use Form H-31 or write your own, Connecticut expects the same core details. At minimum, include:
Full name and address of the buyer (with signature)
Full name and address of the seller (with signature)
Vehicle make, model, year, and color
Vehicle Identification Number (VIN)
Odometer reading
Sale price
Date of sale
The Connecticut DMV also notes that its official H-31 form doesn't include a line for the buyer's signature, but recommends buyers sign anyway for extra protection. It's a small step that can save a lot of confusion later.
A Quick Tip on the Odometer Reading
Don't round the mileage. Write down the exact number showing on the dashboard at the time of sale. This figure matters for two reasons: it satisfies the federal odometer disclosure requirement, and it protects the buyer if there's ever a dispute about mileage down the road.
Do You Need to Notarize a Bill of Sale in Connecticut?
No. Connecticut does not require notarization for a standard private-party vehicle bill of sale. A signed document with both parties' signatures is generally sufficient for the DMV.
That said, notarizing is never a bad idea if you want extra legal protection, especially for a higher-value vehicle. It's optional, not required.
Connecticut Sales Tax on Private Vehicle Sales
This is where a lot of buyers get caught off guard. Connecticut doesn't collect sales tax through the seller in a private sale — you pay it directly to the DMV when you register the vehicle.
According to the Connecticut DMV, the standard vehicle sales tax rate is 6.35%, based on either the bill of sale price or the NADA average trade-in value, whichever is higher. If the vehicle's price exceeds $50,000, the rate jumps to 7.75%.
Sales tax isn't unique to Connecticut, and it isn't small money for the state either. In fiscal year 2024, Connecticut's Department of Revenue Services collected roughly $6.4 billion in total sales and use tax revenue — a good reminder that this isn't a formality the state takes lightly.
There are a few exceptions. The Connecticut DMV outlines two big ones:
No sales tax is due if the vehicle is sold or transferred to a mother, father, sister, brother, son, daughter, husband, or wife — as long as it was registered in that family member's name for at least 60 days before the transfer.
No sales or use tax applies to a vehicle received as a genuine gift, though the donor may face separate Connecticut gift tax rules.
When You Might Not Owe Sales Tax
1
Immediate family transfers
2
Gifted vehicles
If you think you qualify for an exemption, you'll need to complete the right form at the time of registration — don't assume it'll be applied automatically.
Sales Tax at a Glance
| Situation | Tax Rate |
|---|---|
| Vehicle price $50,000 or less | 6.35% |
| Vehicle price over $50,000 | 7.75% |
| Sale/transfer to immediate family (60+ days registered) | Exempt |
| Vehicle received as a gift | Exempt |
| Active-duty military purchasing from a licensed CT dealer | 4.5% |
How Registration Works After the Sale
Once the bill of sale is signed, the clock starts ticking. Here's the general flow buyers follow:
Collect the signed title, the completed bill of sale, and proof of Connecticut insurance.
Make an appointment at a Connecticut DMV office — walk-ins aren't guaranteed, and some locations, including Cheshire, Putnam, and Stamford, don't offer walk-in service at all.
Bring a valid photo ID.
Pay the applicable sales tax and registration fees.
Receive your new registration and title paperwork.
If your vehicle is four model years or older, it will also need an emissions test or VIN verification before registration is complete.
New Connecticut residents bringing a vehicle from another state get a little more breathing room — they have 90 days to transfer their registration after establishing residency.
How Many Copies of the Bill of Sale Do You Need?
A good rule of thumb: make three copies — one for the buyer, one for the seller, and one to leave with the DMV. It's a five-minute task that saves you a scramble later if either party needs proof of the sale for taxes, insurance, or a future dispute.
If you're selling a vehicle that's being scrapped or junked, hold onto that bill of sale even longer. Connecticut requires it, along with a canceled plate receipt, if you want a credit on motor vehicle property taxes.
Common Mistakes to Avoid
A few small errors show up again and again on Connecticut bill of sale transactions:
Leaving the sale price blank or writing "gift" to dodge tax. The DMV compares your stated price against NADA trade-in values, and understating the price can trigger scrutiny or back taxes.
Skipping the buyer's signature. Even though the state form doesn't require it, it's smart protection for both sides.
Mismatched VINs. Double-check that the VIN on the bill of sale matches the one on the title, the dashboard, and the door jamb — character for character.
Forgetting the odometer reading. This is a federal requirement for most vehicles under 20 model years old, not just a Connecticut rule.
Not making copies. Once the deal is done and everyone's gone home, getting a signature again is a lot harder.
Bill of Sale vs. Title: Quick Comparison
People mix these two up constantly, so here's the difference laid out plainly.
| Document | What It Proves | Required for Registration? |
|---|---|---|
| Bill of Sale (Form H-31) | Transaction details: price, date, parties, VIN, odometer | Yes |
| Vehicle Title | Legal ownership of the vehicle | Yes |
Both documents work together. Neither one replaces the other.
Selling Privately? Here's Where KarKiosk Helps
Getting the paperwork right is only half the job — the other half is actually finding a buyer who's ready to move forward. That's where KarKiosk comes in. Listing your car privately means you skip dealer trade-in markdowns and keep more of the sale price in your pocket, while KarKiosk helps you connect with serious buyers without the back-and-forth.
Once you've got a buyer lined up, the bill of sale steps above are exactly what you'll walk through together to close the deal.
