If you are interested in the purchase or sale of a small business, you may have many legal needs. Our firm can help you with various small business matters.We'll discuss seller financing for business and how it works, as well as highlight the pros and cons for both buyers and sellers. You will need a promissory note and security agreement that addresses the key terms of the seller note. Typically, this involves two documents: a financing agreement (basically a loan document outlining the details and terms of the loan) and a promissory note.