In the loan contract, the maximum penalty for overdue repayment is 4 times of the bank's listing interest rate in the same period. The bank loan interest rate is four times in the same period, generally referring to the benchmark loan interest rate published by the People's Bank of China. For example, the current benchmark interest rate for one-year loans is 6%, so four times is 24%.
Legal basis: Some opinions on people's courts' handling of loan cases: Article 6 The interest rate of private loans may be appropriately higher than that of banks, and local people's courts may specifically grasp it according to the actual situation in their own regions, but the maximum interest rate shall not exceed four times (including interest rate) of similar loans of banks. Beyond this limit, the excess interest will not be protected.