A business sale agreement is a legal document that describes and records the price and other details when a business owner sells the business. Identify the parties involved in the transaction. 2.Set it up as a template. Use and store this free template to specify obligations between sellers and buyers. From drafting to signing, Contractbook is with you every step of the way. A Business Purchase Agreement is a contract that transfers a business entity from its owner to a new buyer. A business purchase agreement is a legal contract specifying terms for buying or selling a business, including conditions and obligations.