A method and system for provisioning authorization for use of a service in a communications network. In response to a dialed feature code by a subscriber, a network entity may modify the subscriber's profile maintained by a serving system to authorize use of a service by the subscriber as indicated by the feature code. Alternatively, the subscriber's profile may be modified to prohibit use of the service as instructed by the dialed feature code. Therefore, the subscriber may effectively subscribe to or unsubscribe from a service in this manner by dialing a feature code.