To perform settlement confirmation processing by telephone in accordance with the convenience of a user side while acquiring security by utilizing telephone for the authentication of a credit card in the case of performing Internet shopping by using the credit card.

A telephone used to inquire settlement approval is designated among one, two or more telephone numbers that are preliminarily registered in a credit card company by the user to inquire credit card payment approval when the user does shopping. An Internet shop transmits the information of a settlement request and information for specifying the telephone to be used for inquiry to the credit card company, and the credit card company connects a telephone to the telephone desired by the user at his/her desired time/time period to request the user to input person himself/herself identification information from the telephone. Thus, the credit card company confirms the user himself/herself and performs settlement confirmation.