Having a printable copy of your car's bill of sale is necessary to protect you from certain legal issues. If you are a seller, the bill of sale proves that you sold the car to a certain buyer and are no longer responsible for it. For the buyer, it provides a record of the transaction and information such as the date of the sale and the price of the vehicle.
States such as California, Montana, Virginia and Washington require a signed and dated bill of sale as part of the documents necessary to complete a title transfer. Regardless of your state's requirements, the bill of sale proves that a transaction took place and provides general information about both the buyer and the seller.
As a seller, if you do not have a printed copy of a car's bill of sale, you may face legal issues if the buyer commits traffic violations, such as getting tickets or causing accidents, while using the vehicle. The bill of sale proves that the transaction took place on a specific date and that you no longer own the vehicle.
As a buyer, the bill of sale has information that you can check against the vehicle history report. The information on the bill of sale also makes it easier for you to register the vehicle.