A mobile communicator including a main housing portion, defining a SIM card socket, a battery located at a battery location defined by the main housing portion, a cover over the battery and a retrofit contactless smart SIM functionality assembly, having a SIM card shaped portion which is mounted in the SIM card socket, a contactless smart card antenna portion located between the battery and the cover and an antenna tail portion which interconnects the contactless smart card antenna portion with the SIM card shaped portion, the antenna tail portion being attached and electrically connected to the SIM card shaped portion by means of an electrically conductive adhesive.