The invention relates to a method for displaying a piece of information, using a mobile ID transmitter (10) and a cellular telephone (20) having a display (21), wherein the mobile ID transmitter (10) is used to activate a security system of a motor vehicle, the mobile ID transmitter (10) has an electronics unit (11), the electronics unit (11) is used for data communication (30) with a vehicle-side device, a vehicle-side piece of information is transmitted from the vehicle-side device to the electronics unit (11) by means of the data communication (30), the vehicle-side piece of information is stored in a data memory (12), the electronics unit (11) communicates with the cellular telephone (20) by means of a communication connection (40), and the vehicle-side piece of information is transferred to the cellular telephone (20) by means of the communication connection (40) and displayed there by means of the display (21). Furthermore, the invention is also directed at a system for displaying a vehicle-side piece of information on a cellular telephone (20) by means of a mobile ID transmitter (10) and also only at an ID transmitter.