It is the customer's funds that have been received and unpaid. For example, if a customer wants to buy the products of a fund company, the fund company will cooperate with third-party companies such as Kuaiqian. At this point, after initiating a purchase transaction, Kuaiqian will deduct money from the customer's card, and then Kuaiqian Company will settle the money to the fund company after receiving the money from the bank channel. This process will allow the customer's funds to stay in the account of the third-party payment company for a period of time. This part of the money left in the quick money account is the customer reserve.