A method and system for controlled provisioning of a desired set of service logic for a subscriber of group of subscribers. In response to a designated stimulus, such as a time-event, a location-event or a threshold-event, a network entity modifies the subscriber profile maintained by a serving system, so as to include in the profile one or more desired parameters. One such modification may be the inclusion in the profile of a trigger that directs the serving system to query a designated network entity for call handling instructions. The designated network entity may then provide a special set of services for the subscriber or group. Further, a mechanism is provided to help ensure that once such a service overlay is imposed, it remains imposed if desired.