PURPOSE: To attach the function of merchandise coupon, etc., on a customer card and also, to easily confirm the present accumulated amount by printing a discount target aggregate and discount amount on the print plane of the customer card, and writing the discount target aggregate and the discount amount on an information storage part.

CONSTITUTION: The customer card 20 is provided with the print plane 20a on the surface of it, and a magnetic recording part 20b on the back plane. An issuance number and a customer name, and a use date, the discount target aggregate, and the discount amount are printed on the print plane 20a at every usage, and an issuance company name, customer data (issuance number, customer name), a preceding use date, a preceding purchase amount, the discount target aggregate, and the discount amount are recorded on the magnetic recording plane 20b. Thereby, it is possible to attach the function of merchandise coupon, etc., on the customer card 20, and also, to easily confirm the present aggregate amount.