Legal analysis: 1. It is best for borrowers to write IOUs by hand, but pay attention to the writing norms. Printed IOUs have the same legal effect, but they are easy to forge. The signature of the borrower should also be based on the handprint. The borrower's information must be clearly written with the ID number, and the borrower is required to provide the original for verification when writing the loan. 2. The date of the loan-be sure to write it clearly, preferably accurate to the day. The repayment date can be agreed in the loan slip. If there is no agreed repayment date, the borrower can claim repayment at any time. If the repayment date is agreed, you can only ask for repayment at that time. If the repayment date is not returned, the lender shall file a lawsuit within two years, and may lose the right to win the case after the deadline. 3. The loan amount should be capitalized in Arabic numerals and Chinese at the same time, and the currency should be clearly written, such as "RMB 65,438+000,000.00 Yuan only" to prevent the loan holder from tampering. 4. The payment shall be delivered by bank transfer as far as possible, and the account number and transfer date of the other party may be indicated in the debit note. For transfer, you can indicate the purpose of the loan. If the amount is small, it should be indicated in the IOU that both loans are paid in cash. Either way, the borrower needs to write a receipt for the money received separately. The IOU can only prove that there is a loan contract relationship between the two parties, which is not enough to prove that the borrower has fulfilled the obligation to repay the money. 5. If the borrower is married, it is better to get the signature of the spouse, which is more secure for the creditor, so as to prevent one party from refusing to undertake the repayment obligation or executing it in court on the grounds of ignorance, and one party transfers the property to the spouse, resulting in inability to repay. 6. After the IOU is issued, a copy of the borrower's autographed ID card and a copy of the marriage certificate shall be collected at the same time. 7. If the amount is large, you can ask a lawyer or a third party to witness and sign it.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 667 A loan contract is a contract in which the borrower borrows money from the lender, repays it at maturity and pays interest.

Article 668 A loan contract shall be in written form, unless otherwise agreed between natural persons. The contents of a loan contract generally include terms such as loan type, currency, purpose, amount, interest rate, term and repayment method.

Article 669 When concluding a loan contract, the borrower shall provide the true information about the business activities and financial status related to the loan according to the requirements of the lender.