A charging management server is informed of an ED number stored in an IC card, and a user charging table of the charging management server is read. A new user charging list is transmitted to an MFP. In the case where the MFP receives a cooperative job to be executed by a cooperative server, a sub charging list is generated. The generated new sub charging list is transmitted together with image data to the cooperative server. The cooperative server executes the job on the basis of charging a fee for the job. As the job is executed on the basis of charging, the sub charging list is updated. In parallel with the execution of the cooperative job by the cooperative server, the WP can perform a normal job according to the charging list.