An image forming apparatus includes a connector to which a cartridge containing printing material is connectable and a controller. The controller stores a subscription status indicating whether a user is subscribed to a specific service, acquires first information indicating a residual quantity of the printing material, transmits the first information to a sever, and determines whether the user is subscribed to the specific service. Under the specific service, a new cartridge is delivered by transmitting the first information. When not subscribed to the specific service and the residual quantity is a first threshold value or less, the controller notifies the user that the residual quantity is low. When subscribed to the specific service and the residual quantity is a second threshold value or less, the controller notifies the user that the residual quantity is low. The second threshold value is below the first threshold value.