Hillsborough Community College (HCC) uses Supplier Registration as the College's web-based vendor registration and solicitation management system. A Business Purchase Agreement is a contract that transfers a business entity from its owner to a new buyer.You will also need to submit a completed W9 form. Identify the parties involved in the transaction. 2. A business sale agreement is a legal document that describes and records the price and other details when a business owner sells the business.