Using a preset, temporary ID, a user accesses an on-line shop where he is not registered. When the user buys a commodity, the on-line shop sends order data to a money gate. In response to a request from the money gate, a mall-operating company where the user is registered sends the money gate information necessary for settlement such as a credit number. The money gate generates final order data by combining the order data and the information necessary for settlement. Settlement processing with a card company is performed by using the final order data.