To provide a customer data control system capable of collectively controlling customer data on both a department/shop of a transferor and a department/shop of a transferee when transferring a customer in charge of a certain department/shop to the other department/shop.

This customer data control system controls the customer data including customer attribute information being customer-related information and business information to the customer, and is provided with a server 102 for retrieving the customer attribute information of the transferor by using a former department/shop code and a former customer code by including a department/shop code proper to the department/shop and a customer code proper to the customer in the department/shop in the customer attribute information by controlling the customer data, and respectively including the department/shop code and the customer code included in the customer attribute information on the transferor in the customer attribute information on the transferee as the former department/shop code and the former customer code when transferring the customer between the departments/shops, and clients 103 and 103A for inputting-outputting the customer data.