An image forming apparatus providing services for general users, capable of getting rid of trouble to collect use charges. The image forming apparatus has: a connector to which a portable communication terminal is connected; a communication section for controlling the portable communication terminal connected to the connector, and controlling communication with the portable communication terminal and a management apparatus; a reading section for reading authentication information out of the portable communication terminal; an inquiry request section for sending the authentication information to the management apparatus, and requesting the management apparatus to inquire the electronic prepaid information based on the authentication information; a receiving section for receiving the electronic prepaid information replied by the management apparatus through the communication section; and an image forming control section for controlling whether to perform image forming processing or not on the basis of the electronic prepaid information.