A network device receives a personal Mobile Directory Number (MDN) associated with an individual subscriber, wherein the individual subscriber is further associated with one or more subscriber devices. The network device receives an additional MDN assigned to the individual subscriber, and sends a notification, requesting the individual subscriber's acceptance of the additional MDN assigned to the individual subscriber, to at least one of the one or more subscriber devices. The network device receives, from one of the one or more subscriber devices, an acceptance of the additional MDN from the individual subscriber. The network device links the additional MDN, the personal MDN, and the one or more subscriber devices, within an Implicit Registration Set (IRS) at a Home Subscriber Server (HSS) in an Internet Protocol Multimedia Subsystem (IMS) network for routing calls to the individual subscriber's additional MDN or personal MDN at the one or more subscriber devices.