Legal analysis: 1. IOU format: IOU generally consists of three parts: title, body and payment. (1) The title of the IOU generally consists of the name of the language, that is, the word "IOU" is written in a larger font in the middle of the text above. Some also write the words "arrears" or "owe now" as the title in this position, but the text of this title is written in the top box of the next line. (2) The text of the IOU should state clearly who or what unit is owed, what the amount is, and the date of repayment should be indicated. (3) The payment must be signed with the name of the debtor's unit and the signature of the person handling it. If the IOU is issued by an individual, the name of the individual who owes the debt must be signed. And also sign the date of the IOU. The unit's official seal must be stamped, and the individual's private seal must be stamped. It is best to make two copies, signed by both parties; write the currency clearly, in both upper and lower case letters, and the handwriting must be clear.

Legal basis: Article 667 of the "People's Republic of China and Civil Code" A loan contract is a contract in which the borrower borrows money from the lender, returns the loan and pays interest when due.