The title of the car is the most important paperwork. Along with information about the car’s make, model, year, VIN, and name, this serves as proof of ownership. The lienholder, typically the bank, will have the title if you are still in debt for the vehicle. The loan must be repaid before you can get a clear title.
A bill of sale is not required, but it is strongly advised. It functions as a written record of the transaction, including information on the car, the purchase price, the date of the transaction, and the signatures of the two parties.