Method, apparatuses and computer programs for handling data related to users of a communications system comprising: a database server storing data related to users of the system, and a plurality of service servers. The database server modifies (1103) a first data stored therein for a user according to a received request (1101), and sends a second message (1109) notifying the data modification to a first service server comprising: an identifier of the user, the first data after the modification, and an identifier of a second service server of the system that handle data related to the user. The first service server sends a third message (2105) to the second service server requesting to modify a data held therein in relationship with said user. Features of the invention help in reducing signaling in layered systems, since additional data are communicated in the second message.