Consuming device operating while consuming consumable and consumption management system including server and the consuming device

A consumption management system comprising:

• a server;
• and
• a consuming device comprising:
• a holder configured to hold therein a consumable;
• a display;
• and
• a controller,
• wherein the consuming device is operable in an operating mode, the operating mode being switchable between a billing mode in which the consuming device can consume the consumable within a permitted consumption quantity and a non-billing mode in which the consuming device can consume the consumable without any restriction imposed by the permitted consumption quantity,
• wherein the controller of the consuming device is configured to perform:
• (a) setting the operating mode to one of the billing mode and the non-billing mode;
• when the operating mode is set to the non-billing mode in (a):
• (b) executing, in response to receiving an execution instruction, a prescribed operation consuming the consumable, the prescribed operation being executed in (b) while consuming the consumable irrespective of the permitted consumption quantity without decreasing the permitted consumption quantity;
• when the operating mode is set to the billing mode in (a):
• (c) acquiring the permitted consumption quantity including a newly purchased consumption quantity paid for by a user;
• (d) displaying the permitted consumption quantity on the display;
• and
• (e) executing, in response to receiving the execution instruction, the prescribed operation, the prescribed operation being executed in (e) while consuming the consumable and decreasing the permitted consumption quantity acquired in (c) until the decreased permitted consumption quantity reaches a predetermined quantity, and
• wherein when the operating mode is set to the non-billing mode in (a), the controller of the consuming device does not display the permitted consumption quantity on the display.

A non-transitory computer-readable storage medium storing a set of computer-readable instructions for controlling a printing device, the printing device including:

• a holder configured to hold therein a printing consumable;
• a display;
• and a computer, the printing device being operable in an operating mode, the operating mode being switchable between a billing mode in which the printing device can consume the printing consumable within a permitted printing quantity and a non-billing mode in which the printing device can consume the printing consumable without any restriction imposed by the permitted printing quantity, the set of computer-readable instructions, when executed by the computer, causing the printing device to perform:
• (a) setting the operating mode to one of the billing mode and the non-billing mode;
• when the operating mode is set to the non-billing mode in (a):
• (b) executing, in response to receiving an execution instruction, a printing operation consuming the printing consumable, the printing operation being executed in (b) while consuming the printing consumable irrespective of the permitted printing quantity without decreasing the permitted printing quantity;
• when the operating mode is set to the billing mode in (a):
• (c) acquiring the permitted printing quantity including a newly purchased printing quantity paid for by a user;
• (d) displaying the permitted printing quantity on the display;
• and
• (e) executing, in response to receiving the execution instruction, the printing operation, the printing operation being executed in (e) while consuming the printing consumable and decreasing the permitted printing quantity acquired in (c) until the decreased permitted printing quantity reaches a predetermined quantity, and
• wherein when the operating mode is set to the non-billing mode in (a), the printing device does not display the permitted consumption quantity on the display.