Abstract: Provided is a method of providing, by a card company server, a card service for setting a condition of card use, the method including steps of: (a) providing a user terminal with a button type interface for setting a condition of card use with respect to at least one of a use range and a use amount of a card owned by a user; (b) processing such that the condition of card use selected through the interface is set; and (c) processing such that payment approval for the owned card is completed on the basis of the set condition of card use when the payment approval is requested.

Abstract: Provided are a method of relaying, by a payment gateway server, a payment using a representative card connected to a plurality of general cards, the method comprising steps of: (a) acquiring card information of a card set as a payment card among the plurality of general cards connected to the representative card when a payment approval is requested using the representative card; and (b) requesting the payment approval to a card company server using the acquired card information of the payment card and processing such that the payment approval made using the payment card is completed.