Legal analysis: 3 years. (a) the statute of limitations for private loans with regular repayment is three years from the date of the expiration of the repayment period, and the right to request protection from the people's court is lost after the expiration. (2) For private lending with regular repayment, if the debtor fails to perform the debt after the agreed time limit expires and issues a debt bill with no repayment date, it will be deemed that the limitation of action is interrupted, and the limitation of action will be recalculated from the second day after receiving the debt bill (3 years). (3) Non-regular repayment of private loans, that is, private loans with no repayment date, is not limited by the statute of limitations, but is limited by the maximum protection period of 20 years.

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.