An information output apparatus includes a tray determining unit that determines an output tray to which printed sheets are output, a secret information generating unit that generates first secret information corresponding to tray identification information for identifying the output tray determined, a transmitting unit that transmits the first secret information generated by the secret information generating unit to a terminal, an input accepting unit that accepts an input of second secret information from a user, and a tray controlling unit that specifies the output tray based on the first secret information when the second secret information and the first secret information coincide with each other, and allows a slot of the specified tray to be open.