A slip printing system which can be employed in a service management system is configured to include a host computer, a mobile terminal device, and a mobile printer that is capable of receiving data from the mobile terminal device. The mobile terminal device includes a service information input module. The service information input through the service information input module is transmitted to the host computer. A print data generating module of the host computer generates print data to in accordance with the service information. The print data generated by the print data generating module is transmitted to the mobile terminal device. The mobile terminal device transmits the print data which has been transmitted from the host computer, and the mobile printer prints an image on a slip in accordance with the print data transmitted from the mobile terminal device.