In some examples, a device detects a calling identifier received as part of initiating a call matches an emergency identifier, the emergency identifier associated with information from which to derive a Uniform Resource Name (URN). The device detects that the device is attached to or registered a first network different from a second network, where the second network configured the emergency identifier. In response to detecting that the device is attached to or registered the first network different from the second network, the device includes a Session Initiation Protocol (SIP) Uniform Resource Identifier (URI) in a Session Initiation Protocol (SIP) INVITE message to be transmitted.