Legal analysis: the monthly interest rate 1.5% is equivalent to the annual interest rate 18%, which belongs to usury and is illegal. According to the relevant laws and regulations, the upper limit of judicial protection of private lending is determined by taking the one-year loan market quoted interest rate (LPR) issued by the National Interbank Funding Center authorized by the People's Bank of China as the standard, replacing the provisions based on 24% and 36% in the original Regulations. According to the latest one-year loan market quotation rate of 3.85%, the upper limit of judicial protection of private lending interest rate is 15.4%.

Legal basis: Article 680 of the Civil Code of People's Republic of China (PRC) prohibits high-interest lending, and the lending rate shall not violate the relevant provisions of the state. If there is no agreement on the payment of interest in the loan contract, it shall be deemed that there is no interest. If the loan contract does not specify the payment method of interest, and the parties cannot reach a supplementary agreement, the interest shall be determined according to the local or the parties' trading methods, trading habits, market interest rates and other factors; Loans between natural persons are regarded as interest-free. "Several Opinions on People's Courts' Trial of Lending Cases" Article 6 The interest rate of private lending may be appropriately higher than the bank's interest rate, and local people's courts may specifically grasp it according to the actual situation in the region, but the maximum interest rate shall not exceed four times (including interest rate) of similar loans from banks. Beyond this limit, the excess interest will not be protected.