Yes, you need a bill of sale. State the terms and odometer reading on the BOS.Edit, sign, and share vehicle purchase agreement with deposit online. No need to install software, just go to DocHub, and sign up instantly and for free. Signature of Seller. A car (vehicle) purchase deposit receipt is written proof that a potential buyer of a car has supplied the seller with a deposit. Check out our free bill of sale form selection for the very best in unique or custom, handmade pieces from our templates shops. Looking for a bill of sale to use for your business? We've got a template ready to be customized for your needs today. A guy I'm potentially selling my car too says he needs a bill of sale to give the bank before they give him a loan?