A bill of sale is a legal document that attests to the transference of ownership of property. It lists the details of the sale, including the specific date of the sale, the sum of value received by the seller from the buyer (this sum may be a full or partial payment), and the specifics of the item or property sold. Bills of sale also include a portion wherein both parties expressly states their acceptance of the conditions listed on the bill of sale.
The bill of sale came into existence to help prevent fraud. Before bills of sale, people were able to sell and resell property that they do not fully own (still being paid for) without either the new buyer or the original seller finding out until it was too late. With a bill of sale, buyers were able to ask for and present proof that they had complete ownership of a property, or at least the right to sell that property.
There are two kinds of bills of sale: the absolute bill of sale and conditional bill of sale.
The absolute bill of sale indicates the transference or sale of property has been fulfilled in whole and that a buyer has total ownership and control of a property. There is no security needed for an absolute bill of sale.
A conditional bill of sale states that the buyer needs collateral, or another form of security before the sale can be completed.