1. It is best for borrowers to write IOUs by hand, but pay attention to the writing standards. Printed IOUs have the same legal effect, but they are easy to forge. The borrower's signature should also be thumbprinted. The borrower's information must be clearly written with the ID number, and the borrower should be required to provide the original for verification when writing the loan.

2. The date of the loan-must be clearly written. How to write IOUs should be accurate to the day. The repayment date can be agreed in the IOU. If there is no agreed repayment date, the borrower can claim repayment at any time. If the repayment date is agreed, the request can only be made when the repayment date expires. 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 100000.00 Yuan only" to prevent the loan holder from tampering.

4. Payment shall be made by bank transfer as far as possible, and the account number and transfer date of the other party may be indicated on the debit note. When handling the transfer, you can indicate the purpose of the loan. If the amount is small, it should be indicated on the IOU that both parties' 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.