A beverage or foodstuff preparation machine comprising: a container processing subsystem to process a beverage or foodstuff container to prepare a beverage or foodstuff therefrom: a control subsystem to control the container processing subsystem to prepare the beverage or foodstuff; a consumption monitoring subsystem configured to monitor consumption of containers by said container processing subsystem and to determine therefrom container consumption information relating to said consumption and; a networking subsystem comprising a wireless network interface for communication with an external portable electronic device over a network, wherein the wireless network interface is for example a Bluetooth TM or a near field communication interface; wherein the consumption monitoring subsystem is configured: - to store stock state information, which comprise information relating to an amount of containers at a location of the machine; - to update said stock state information using the consumption information; receive, via the networking subsystem, stock order information, which comprises information detailing an amount of containers purchased by a user; - and to further update the stock state information using said stock order information; - and to transmit, via the networking subsystem, said further updated stock state information to said portable electronic device characterised in that the consumption monitoring subsystem is further configured: - to receive, via the networking subsystem, a first stock order identifier which is associated with stock order information; - to compare the first stock order identifier to a second stock order identifier stored on the portable electronic device or said machine; - to determine if said identifiers are different, and if different: store the first stock order identifier as the second stock order identifier or as a further second stock order identifier on either the portable electronic device or the said machine; - to update the stock state information using the stock order information associated with the first stock order identifier. a control subsystem to control the container processing subsystem to prepare the beverage or foodstuff; a consumption monitoring subsystem configured to monitor consumption of containers by said container processing subsystem and to determine therefrom container consumption information relating to said consumption and; a networking subsystem comprising a wireless network interface for communication with an external portable electronic device over a network, wherein the wireless network interface is for example a Bluetooth TM or a near field communication interface; wherein the consumption monitoring subsystem is configured: - to store stock state information, which comprise information relating to an amount of containers at a location of the machine; - to update said stock state information using the consumption information; receive, via the networking subsystem, stock order information, which comprises information detailing an amount of containers purchased by a user; - and to further update the stock state information using said stock order information; - and to transmit, via the networking subsystem, said further updated stock state information to said portable electronic device - to store stock state information, which comprise information relating to an amount of containers at a location of the machine; - to update said stock state information using the consumption information; receive, via the networking subsystem, stock order information, which comprises information detailing an amount of containers purchased by a user; - and to further update the stock state information using said stock order information; - and to transmit, via the networking subsystem, said further updated stock state information to said portable electronic device characterised in that the consumption monitoring subsystem is further configured: - to receive, via the networking subsystem, a first stock order identifier which is associated with stock order information; - to compare the first stock order identifier to a second stock order identifier stored on the portable electronic device or said machine; - to determine if said identifiers are different, and if different: store the first stock order identifier as the second stock order identifier or as a further second stock order identifier on either the portable electronic device or the said machine; - to update the stock state information using the stock order information associated with the first stock order identifier. - to receive, via the networking subsystem, a first stock order identifier which is associated with stock order information; - to compare the first stock order identifier to a second stock order identifier stored on the portable electronic device or said machine; - to determine if said identifiers are different, and if different: store the first stock order identifier as the second stock order identifier or as a further second stock order identifier on either the portable electronic device or the said machine; - to update the stock state information using the stock order information associated with the first stock order identifier.