Legal analysis: If the debtor doesn't press the fingerprint and you sign it, then the debtor doesn't admit that he entrusted you to write it, and the borrower will blame you if he can't get the money. You have no evidence to prove that the money was given to the debtor, and you should bear legal responsibility. 1. If it is entrusted by the debtor, it is necessary to obtain the debtor's written authorization, because oral authorization may be troublesome if it is not recognized at that time. 2. If you go to court because of this, you can explain the relevant process clearly and just write an iou. You can't assume that you have paid back the money. Even if the debtor doesn't pay back the money or doesn't admit the existence of the loan, it will generally not bear the responsibility unless you have a guarantee clause in the debt.

Legal basis: Article 188 of the Civil Law of People's Republic of China (PRC) requests the people's court to protect civil rights, and the limitation of action is three years. Where there are other provisions in the law, those provisions shall prevail. The limitation period of action shall be counted from the date when the creditor knows or should know that the right is damaged and the debtor knows it. Where there are other provisions in the law, those provisions shall prevail. However, the people's court shall not protect the rights that have been damaged for more than 20 years. Under special circumstances, the people's court may decide to extend the time according to the application of the obligee.