A Car Bill of Sale is a legal document that records the transfer of ownership of a motor vehicle from the seller to the buyer in a private party transaction. The bill of sale serves as proof of the transaction, documenting the vehicle identification, purchase price, condition, and the identities of both parties. Every state requires some form of documentation to effectuate a vehicle title transfer, and in most states, the bill of sale is either required by the Department of Motor Vehicles (DMV) or strongly recommended as a supplementary document to the signed title certificate.

Vehicle sales in private transactions are governed by a combination of state motor vehicle codes, the Uniform Commercial Code (UCC) Article 2, and federal regulations. The Federal Odometer Act (49 U.S.C. Sections 32701-32711) requires sellers to provide a written odometer disclosure statement in connection with the transfer of motor vehicles, with criminal penalties for odometer tampering or fraud. Under the Act, the seller must disclose the vehicle's mileage at the time of transfer and certify whether the odometer reading reflects the actual mileage, exceeds the odometer's mechanical limits, or is not the actual mileage due to a discrepancy.

State "lemon laws" generally do not apply to private party used car sales, but buyers are protected by common law doctrines of fraud and misrepresentation. If a seller knowingly conceals a material defect or makes false statements about the vehicle's history (such as undisclosed accident damage, flood damage, or salvage title status), the buyer may have legal recourse under state consumer protection statutes and common law fraud claims regardless of any as-is disclaimer. Services such as the National Motor Vehicle Title Information System (NMVTIS), maintained by the Department of Justice, provide title history, odometer readings, and salvage or junk designations to help buyers verify a vehicle's history.

An individual is selling their personal vehicle to another private party and needs a written record of the sale to protect against future liability, such as parking tickets, toll violations, or accidents that occur after the transfer. A buyer is purchasing a used car from a private seller and needs documentation for the DMV title transfer and registration process.

A seller is providing the buyer with a bill of sale to satisfy the DMV's proof of purchase requirement for calculating the sales tax or use tax owed on the vehicle purchase. A family member is gifting or selling a vehicle to another family member at below market value and needs documentation for the title transfer that reflects the transaction as a gift or nominal sale for tax purposes.

A car owner is selling a vehicle that has an outstanding loan, and the bill of sale documents the sale terms while the parties arrange for the lien to be paid off and the title released by the lender. An executor or administrator of an estate is selling a deceased person's vehicle and needs documentation for the probate court and the DMV title transfer.

An individual is selling a vehicle in a state where the DMV does not provide a standard bill of sale form, or needs a more detailed document than the state's minimal form, to fully document the vehicle's condition, warranty status, and the terms of the transaction.

The seller's and buyer's complete identifying information must include full legal names, addresses, phone numbers, and driver's license numbers. These details connect the parties to the transaction and are required by most state DMVs for title transfer processing.

The vehicle description must include the year, make, model, trim level, body type, color, Vehicle Identification Number (VIN), license plate number, and current odometer reading. The VIN is the 17-character identifier required on all vehicles manufactured after 1981, encoded with information about the manufacturer, model, engine type, and production sequence. The VIN on the bill of sale must match the VIN on the title certificate and the physical VIN on the vehicle.

The odometer disclosure statement is federally required under 49 U.S.C. Section 32705. The seller must certify the odometer reading and indicate whether the reading reflects the actual mileage, the mileage exceeds the odometer's mechanical limits, or the reading does not reflect the actual mileage (odometer discrepancy). Falsifying an odometer disclosure is a federal crime punishable by fines and imprisonment.

The purchase price must be stated in both numerals and written words. The payment method and terms should be documented. If financing is involved, the lender's name and loan terms should be noted. The state sales or use tax is typically calculated based on the purchase price stated in the bill of sale, though some states use the fair market value (book value) if the stated price is significantly below market.

The warranty status must be clearly stated. Private sellers typically sell vehicles as-is, and the as-is disclaimer must be conspicuous under UCC Section 2-316. The condition of the vehicle at the time of sale should be documented, including any known defects, prior accident damage, flood damage, or salvage/rebuilt title history.

Both parties must sign and date the bill of sale. Some states require notarization for vehicle title transfers. The seller should provide the buyer with the signed title certificate, bill of sale, odometer disclosure, any emissions or safety inspection certificates required by the state, and release of lien documentation if the vehicle was previously financed.