In an image forming apparatus, a consumable is mounted in the main casing. The consumable includes a consumable memory. A controller performs a consumable determination process to determine based on type information stored in a consumable memory whether the consumable mounted in the main casing is a special consumable. The controller performs a transmission process in a case where the consumable determination process determines that the consumable mounted in the main casing is the special consumable. The transmission process transmits via the communication interface a request to an external device which communicates with the image forming apparatus. The request is to cancel an agreement which is concluded for another image forming apparatus as a contract subject. The another image forming apparatus is different from the image forming apparatus.