An image forming apparatus includes: a sensor that detects discontinuation of printing or a decrease in print speed; and an electric circuit configured to set an available time to print according to an amount of advance payment; count a usage time during which the image forming apparatus is used; determine permission or prohibition of printing based on the available time to print and the usage time; determine whether to count the usage time based on a factor for the discontinuation of printing or the decrease in print speed when the sensor detects the discontinuation of printing or the decrease in print speed; and prohibit printing when the counted usage time reaches the available time to print.