First of all, from a legal point of view, an IOU is a written document indicating the relationship between creditor's rights and debts, which is generally written and signed by the debtor, indicating that the debtor has owed the creditor the amount indicated on the IOU. As long as the borrower has the corresponding capacity for civil conduct, the loan facts are objective and true, and the borrower voluntarily signs and confirms, no matter whether the loan is handwritten or printed by computer, it has legal effect. Therefore, the IOU can be printed and signed. The printed IOUs shall be signed by the borrower, indicating that the borrower knows and recognizes the contents of the IOUs, and the printed IOUs shall be valid with the borrower's signature. In daily life, whether printed or handwritten, we should pay attention to the following aspects in content: First, the loan amount should be capitalized. Second, the lender must personally see the borrower's signature. Third, the words and sentences of IOUs should not be ambiguous and there should be no typos. Write "loan" instead of "debt" at the same time. Don't make mistakes. IOUs should reflect the creditor's rights and debts of both parties. Four, when the interest rate is agreed, the interest rate should comply with the provisions. 5. If there is an agreed repayment date, the date should be stated, so as to avoid disputes over the limitation of action caused by unclear repayment date. Sixth, it is necessary to reflect the date of borrowing.

Legal objectivity:

"Notice issued by the Supreme People's Court" X. The loan relationship formed by one party against the true meaning by means of fraud, coercion or taking advantage of the danger of others shall be deemed invalid. If the loan relationship is invalid due to the creditor's behavior, only the principal will be returned; If the debtor's behavior causes an invalid loan relationship, in addition to returning the principal, interest should also be paid with reference to the bank's similar loan interest rate.