To provide a method and a system for issuing a member's card which make it possible to use the member's card already owned by a customer for member's cards for a plurality of stores as well and can reduce the cost of the store side required for issuance of the card and the troublesomeness on the customer side, by utilizing only the ID number of the card.

The ID of the card the customer owns is read by a card reader (S1), while the information on the customer is inputted by a data input device (S2). These ID and customer information are made to correspond to each other and stored in a customer database (S3), and a registered identification tag is provided in the card the customer owns (S4).