Print data including a provisional registration command is received. When the print data including the provisional registration command is received, an authentication code is obtained. The authentication code is stored in a user information DB. Provisional registration data is obtained from the user information DB. Then, a list of provisional registration data is displayed. It is determined whether the provisional registration data is selectively input or not. If the provisional registration data is selectively input, user information in which IC card information or biological information and the authentication code are associated with each other is transmitted to an authentication server. The authentication server executes a process of registering the received user information.