Apparatuses, methods, and systems are disclosed for suspending services in a first network while attached to a second network. One apparatus includes a processor and a transceiver configured to communicate with either a first mobile communication network or a second mobile communication network. The processor uses a first service in the first mobile communication network and determines to suspend the first service in order to use a second service in the second mobile communication network. The transceiver sends a first mobility management message indicating that a first registration and the first service are to be suspended and receives a second message as reply to the first MM message, said second message indicating that the first registration and the first service are successfully suspended. The processor uses the second service in the second core network without using the first service.