Abstract: A system according to the invention comprises a subscriber administration logic located at a service control point SCP of an intelligent network, and a subscriber database of a service data point SDP that is associated therewith by CCS signaling. Subscriber records of the subscriber database are created, updated and deleted by the operator, but the create, read/write and delete functions can also be performed via a telephone network associated with the intelligent network. The operator can activate the control without the subscriber noticing it. For example, as a visitor subscriber of a mobile phone network is updated to a mobile phone network, the subscriber data are automatically forwarded to the intelligent network, which creates a subscriber record for the subscriber concerned.