An RV Bill of Sale is a legal document that serves as proof of the sale and transfer of ownership of a recreational vehicle (RV) from a seller to a buyer. A Recreational Vehicle (RV) Bill of Sale is required anytime an RV is sold or transferred between a seller and a buyer.Seller Name (first, middle, last, suffix). How do I fill this out? This is typically one of the first items you'll put on the bill of sale. The motor vehicle seller must insert the sales price, nonresident state and Arizona county tax rates and complete all mathematical calculations.