What does it mean to fill in the reserved mobile phone number of the bank?

The mobile phone number used by customers when opening an account in a bank is usually one of the important ways for banks to keep in touch with customers. According to the announcement issued by the inquiry bank, the reserved mobile phone number of the bank refers to the mobile phone number used by the customer when opening an account in the bank, which is usually one of the important ways for the bank to keep in touch with the customer. When opening an account in a bank, the customer needs to provide his mobile phone number so that the bank can keep in touch with him by SMS or telephone.