Clearly print or type all information, except signatures. This is typically one of the first items you'll put on the bill of sale.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. Instructions. The new owner's social security number, taxpayer identification number (TIN), or federal employer identification number (EIN) is required. A Recreational Vehicle (RV) Bill of Sale is required anytime an RV is sold or transferred between a seller and a buyer. How do I fill this out?