A Sales and Purchase Agreement (SPA) is a legal contract that details the agreement's terms and conditions. Identify the parties involved in the transaction. 2.Which entity is likely to be the target company (on a share sale) or the seller (on an asset sale)? Download our business purchase agreement templates for free, and ensure that you have a smooth and easy sale process. 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. A buy and sell agreement stipulates how a partner's share of a business may be transferred should that partner die or leave the business.