An information processing system includes a transmitter, wherein upon detecting that a user is authenticated; that a mobile terminal apparatus is present within a predetermined range from a server; and that print data is input from each of plural mobile terminal apparatuses to the server, the transmitter transmits: a print confirmation report to a first mobile terminal apparatus detected to be within the predetermined range, a report, that indicates an image forming apparatus is being used by the user owning the first mobile terminal apparatus, to a second mobile terminal apparatus, and the print data to the image forming apparatus after attaching authentication information to the print data received from the first mobile terminal apparatus, only upon detecting that the user of the first mobile terminal apparatus has approved the printing in response to the print confirmation report. The image forming apparatus prints the transmitted print data.