You will need a promissory note and security agreement that addresses the key terms of the seller note. This is a loan the seller makes to the buyer to facilitate the sale.Use a Business Bill of Sale to set out the terms for the sale of a business and transfer the ownership and all assets to the buyer. The Bill of Sale is the document which evidences the seller's transfer of the business and its assets to the buyer. Learn more about the terms of a purchase and sale agreement. Contact Attorney Peter Chase for more information. What Documents Need to be Drafted In a Sale with Seller Financing?