Basic personal data of an individual is stored as different data files based on content or intended use. The selection of personal data for inclusion in a data file may be performed in accordance with service provider requests or by the end user, preferably with the assistance of templates. Each data file is assigned a unique identifier and is preferably stored in a network server (or, alternatively, in the user's mobile device). The data files may be organized into groups according to content or intended use. For each of the stored files, a graphical symbol is stored in the user's mobile device. When displayed to the user, the symbol preferably resembles a card. Moreover, each group of data files is preferably displayed as a pack of cards. In this manner, the organization of the cards is such that the user can easily select a card needed to obtain a service.