A method of operating a terminal device to establish a radio resource control connection with network infrastructure equipment in a wireless telecommunications network, wherein the terminal device is associated with a previously-allocated temporary identifier that identifies the terminal device within the wireless telecommunications network; the method comprising: transmitting a first message to the network infrastructure equipment comprising an indication of a first portion of the temporary identifier; and transmitting a second message, which is separate from the first message, to the network infrastructure equipment comprising an indication of a second portion of the temporary identifier.