Pennsylvania Trailer Bill of Sale Sample. A Pennsylvania vehicle bill of sale is a legal document formalizing the sale and purchase of a motor vehicle between a buyer and seller.The Trailer is to be sold free and clear of any liens, encumbrances, or mortgages. The buyer and seller should meet at a notary, tag service, or motor vehicle dealer to ensure the title application is completed correctly. Learn about bills of sale in Pennsylvania for vehicles, firearms, animals, etc. The Pennsylvania bill of sale form acknowledges the transfer of possession of a piece of personal property for an agreedupon sum of money. A Pennsylvania bill of sale documents the transfer of ownership of a motor vehicle, boat, gun, or other valuable asset. NOTE: Individuals should list their PA Driver's. Fill forms in a few steps. create. Trailer registration in Pennsylvania doesn't require a bill of sale, but it's still nice to have one.