Use this form to gather necessary information when you sell your vehicle or vessel. Access bill of sale form templates and learn how to transfer ownership of vehicles, boats, firearms, and other high-value personal items in Washington.It is a required document for transferring the title and releases the seller from further liability related to the vehicle. Washington bill of sale forms record the details of a transaction between a seller and a buyer of personal property. A Washington bill of sale is a form that documents the sale or trade of an item from one person to another.