The invention relates to a method and an information system to store and manage client-specific information on identification cards (91) at the request of clients. Client-specific information is detected by an information system (3). Said information is stored in the storage space of a central databank (36) allocated to said clients. Said information is managed by an information system (3) on the basis of instructions received via a communications network (2, 8) and transmitted to the above-mentioned identification cards (91), which are located in terminals (9), by the information system (3) via a communications network (8). The detection of client-specific information and the inputting and transmission of said instructions is carried out using Internet services via the Internet or by means of special brief messages transmitted via a mobile radiotelephone network (8). Client-specific information is updated or loaded, for example, via a mobile radiotelephone network (8) using special short messages or via the Internet (2).