You also need a collateral agreement (often called a UCC filing) if the sale includes physical assets. 1. Sale of Property.Financing. Generally, the buyer will not simply pay cash for the business. Outside or seller financing will need to be arranged. With seller financing, the buyer pays you directly over time, and you still own the asset until the buyer pays off the loan. A seller financing addendum outlines the terms under which the seller of a property agrees to loan money to the buyer to purchase their property. Virginia transaction attorney shares how to write an effective and legally binding business purchase agreement. Seller financing is an agreement in real estate where the seller handles the mortgage process rather than a financial institution. 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.