To make any system other than a user terminal store and transfer settlement data instead in order to reduce the load of the user terminal, and to smoothly perform settlement.

A member store 10 prepares settlement data based on a settlement request received from a user terminal 51, and transmits the settlement data to a data center 20. The data center 20 string-attaches identification information to the settlement data received from the member store 10, and stores the settlement data, and transmits the same identification information as the string-attached identification information to the store member 10. Then, the member store 10 transmits the identification information to the user terminal 51, and the user terminal 51 redirects the identification information received from the member store 10 to a settlement destination 30. The settlement destination 30 transmits the identification information received from the user terminal 51 to the data center 20, and receives the settlement data string-attached with the same identification information as the transmitted identification information from the data center 20. Then, the settlement destination 30 performs settlement processing based on the settlement data.