What information do I need to complete a bill of sale? Payment Agreement Terms.Payment agreements may be available to customers whose property is to be included in an upcoming Lien Sale. This form below is designed for use on upon the sale of a motor vehicle or automobile. Such a bill of sale is needed to confirm a party's ownership in the car. The court has placed the most commonly used forms on line as a resource. Please be advised that the forms detailed below are intended to be a guide. The primary purpose of a bill of sale is to confirm the terms and provide evidence of the transaction between the seller and buyer. Explore the ins and outs of Bills of Sale in our comprehensive guide, ensuring confident and secure buying and selling transactions.