The invention generally related to the field of mobile multimedia middle-ware, computer networking, distributed processing systems, data bases, hand-held computers and wireless communication. A method for conveniently managing user profile information in an unified instant messaging system (7) is proposed. This method operates on a data base structure, which accommodates in a flexible way subscribers' information. More specifically, this method takes into account the mutable characteristics of the environment where subscribers' devices (9) are operating: subscribers can in fact freely modify their personal user profiles (1) as situations change and/or as they move to different geographical locations.