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 first thing to include in a purchase agreement are the full names of the buyer(s) and seller(s).Download our business purchase agreement templates for free, and ensure that you have a smooth and easy sale process. Step 1 – Fill Out the Buyer and Seller Information. 1. Seller. Write down the seller's full name.