Method for processing payment data on at least one of item in mobile device and method for processing the same in payment system

Control method for a payment system for processing data for billing for at least one or more items in accordance with an embodiment of the present invention, a mobile device, the method comprising: receiving a payment bar code issued from the payment server; Merchant server, the method comprising: receiving a payment optimal query request from the mobile device; The merchant server, sending the merchant authentication information, billing information products and membership information to the billing server; Payment server, authenticating the merchant and the customer on the basis of the information received from the merchant server; Payment server, requesting the customer added payment information to the external server; Payment server, comprising: receiving a customer portion of the billing information request from the external server; Payment server, the method comprising: calculating an optimum settlement conditions based on the received billing information added; The mobile device, and outputting the minimum amount for payment in accordance with the optimum condition calculated by the billing server; The mobile device, requesting a payment to the billing server according to the minimum amount for payment in accordance with the output optimal conditions; And a payment server, to perform a payment by the payment request from the mobile device, comprises the step of: transmitting the payment execution results to the merchant server.