A bill of sale is a legal document that records the transfer of ownership of an asset to a second party in exchange for money. A bill of sale is a legal document that shows a transfer of ownership of goods from the seller to the buyer in exchange for compensation.A bill of sale is a piece of documentation which is created to record the ownership of an item of property, in a similar way to a receipt from a merchant. The meaning of BILL OF SALE is a formal instrument for the conveyance or transfer of title to goods and chattels. A bill of sale is a legal document that serves as proof of purchase and, in some cases, records a transfer of ownership — in this case, for a vehicle. A bill of sale is a legal document that outlines the terms of the deal and serves as proof that the vehicle was sold. The purpose of a bill of sales is to be a record of the transfer of ownership. It clearly states who the owner of the item is after the sale. A bill of sale for selling a car serves as proof of purchase and transfer of ownership. It's a combination of a sales receipt and a contract.