• Selling a used car requires a number of different forms, to both ensure the legality of the sale and to notify the state government of the car's new owner. According to the website DMV.org, the exact documents required varies by state. However, there are a number of forms that are required in nearly all areas.
  
  

Driver's License

• In order for the buyer and seller to demonstrate to each other that they are both who they claim to be, they should both produce government-issued identification. While the seller is not forbidden from selling the car to someone who does not have a driver's license, the buyer should be aware that driving without a license is illegal.
  
  

Proof of Insurance

• Although many individuals selling a used car do not demand that the buyer purchasing the automobile has insurance, many used car dealers require that the buyer produce proof of insurance for the new vehicle before allowing the sale to go through. In all 50 states, a person is not allowed to drive a vehicle without being covered by automobile insurance.
  
  

Title

• The rules regarding the process by which the actual title to the car is transferring from one owner to another varies. Many states require that the buyer and seller use a title transfer form, which each party signs. For state rules, a seller should call or visit their local DMV or secretary of state's office before selling the car.
  
  

Bill of Sale

• While not always legally required, it is generally a good idea for the seller to draw up a bill of sale. The bill of sale will list the car being sold -- including the car's vehicle identification number, or VIN -- the date of the sale, and the price for which it was sold. Both parties should sign and date this form.
  
  

Registration

• All cars must be registered with the state to be legally driven. Generally, registrations must be renewed annually. When selling a car, the seller will generally need to produce proof of current registration. Depending on the laws of the state, the buyer may have a grace period of several days, before the expiration of which he must re-register the car with the DMV.
  
  

VIN and Odometer Verification Form

• Although not required in all states, some states require that a person selling a car use a form that records the car's VIN and the current mileage on the car. The buyer should inspect the places on the car where the VIN is marked -- the doors, hood and engine -- and make sure that they match before buying the car.