A subscriber server routes a terminating call in a network that includes a circuit switched (CS) network, a packet switched (PS) network, and an IP Multimedia Subsystem (IMS). The server receives a request for routing information in relation to the terminating call from a CS node in the CS network. A determination is made at server based on whether a UE associated with the terminating call is registered in the IMS and the UE has access to the PS network. The server instructs the CS node to route the terminating call in the CS network when the UE is not registered in the IMS or when the UE does not have access to the PS network. The server instructs the CS node to send the terminating call to the IMS for handling when the UE is registered in the IMS and when the UE has access to the PS network.