The present invention relates to communication system comprising first and second communication devices (11,12) each capable of communicating with a telecommunications network (10), and both being connectable to each other by a data link (17) for information transfer and to a method for operating the same. The first communication device (11) contains individual information, and the second communication device (12) comprises a special memory area (21) for storing individual information acquired from the first communication device (11). To enable an improved and facilitated usage of the system comparator means (22) for comparing the individual information contained in the first communication device (11) with that stored in the special memory area (21) of the second communication (12) device are provided. Therefore, only changes of the individual information of the first communication device (11) are stored in the second communication device (12) after comparing the individual information from the first communication device (11) stored in the second communication device (12) with the individual information in the first communication device (11) when the first communication device (11) is connected again to the second communication device (12).