The main question is what it means to reserve a mobile phone number in a bank card. Leave a commonly used personal mobile phone number when handling bank cards. Bank card reserved information, such as bank card reserved mobile phone number, reserved identity information, work information, etc. The mobile phone number reserved for bank cards means that when handling bank cards, you need to provide a mobile phone number as the contact information and bind the mobile phone number with the bank card. The reserved mobile phone number is used to facilitate communication and notification between banks and cardholders, such as sending transaction short messages and security verification. At the same time, reserving the mobile phone number is also one of the important bases for banks to verify the identity of cardholders, which is used to prevent credit card theft, fraud and other risks. The reserved mobile phone number information can help users identify the correct mobile banking website. If the reserved mobile phone number of the bank card does not match, the user cannot receive the SMS verification code when transferring or paying, and the transfer cannot be successful. You need to bring your valid personal identification to the service desk of the issuing bank's service outlets to apply for changing your mobile phone number.