An image forming apparatus includes a code number generator that generates, when an operation reception unit receives user's designation of a number of tickets to be issued, a code key, and an encryption method, an encrypted code number for each of the designated number of tickets, with respect to each ticket number sequentially allocated to the designated number of tickets, using the designated code key and encryption method, a distinction image generator that generates, for each tickets, a distinction image containing the code number generated for each of the ticket, and a controller that adds, in each of the designated number of tickets, the distinction image of each of the tickets generated by the distinction image generator, to image data of an original of the ticket read by a document reading unit, and causes a printing unit to print each of the designated number of tickets.