The image forming apparatus includes an image forming portion that synthetically prints image data and ID image data specific to a user on a recording paper, a paper discharge tray that discharges and accumulates the recording papers, and an ID image reading portion that reads the ID images of the recording papers accumulated in the paper discharge tray, and notifies an external device specified by a user corresponding to the read ID image that the recording papers in the paper discharge tray must be removed. The image forming apparatus includes an output condition setting portion that sets output conditions of the recording papers, and the image forming portion prints the image data on a recording paper and the ID image data on an edge of the recording paper in accordance with the output conditions set by the output condition setting portion.