County of Harris. §. It contains information about the buyer and the seller, a description of the vehicle being sold, and information about the transaction, such as price.A bill of sale is a legal document that outlines the purchase of property between a buyer and seller. It commonly includes both parties' information. Use our Texas bill of sale form that takes into consideration state requirements. Learn how to legally buy and sell property in Texas. How to fill out the Texas Vehicle Bill of Sale Form? 1. Enter the seller's name and address. 2. Sell personal property with the help of our customizable Bill of Sale forms and examples. Download one of our bill of sale forms to transfer ownership of an item from one person to another.