A communications device configured to transmit signals to and/or receive signals from an infrastructure equipment of a mobile communications network, the communications device comprising a receiver configured to receive signals transmitted by the infrastructure equipment in accordance with a wireless access interface, a transmitter configured to transmit signals to the infrastructure equipment in accordance with the wireless access interface, and a controller configured to control the transmitter and the receiver to transmit data to the infrastructure equipment via an uplink of the wireless access interface or to receive data on the downlink of the wireless access interface, wherein the wireless access interface can provide a plurality of different spacing of subcarriers for transmitting signals representing the data on the uplink or for receiving the signals representing the data on the downlink, and the controller is configured in a combination with the transmitter and the receiver when the infrastructure equipment identifies a requirement to provide communications resources of the wireless access interface on the uplink for the communications device to transmit data to the infrastructure equipment or on the downlink for the communications device to receive data from the infrastructure equipment, to receive an indication (430, 454) on a downlink of the wireless access interface of one of the plurality of different subcarrier spacing which the communications device should use to transmit or to receive the signals representing the data, the indicated subcarrier spacing also determining whether the communications device should use a single subcarrier or multiple subcarriers. a receiver configured to receive signals transmitted by the infrastructure equipment in accordance with a wireless access interface, a transmitter configured to transmit signals to the infrastructure equipment in accordance with the wireless access interface, and a controller configured to control the transmitter and the receiver to transmit data to the infrastructure equipment via an uplink of the wireless access interface or to receive data on the downlink of the wireless access interface, wherein the wireless access interface can provide a plurality of different spacing of subcarriers for transmitting signals representing the data on the uplink or for receiving the signals representing the data on the downlink, and the controller is configured in a combination with the transmitter and the receiver when the infrastructure equipment identifies a requirement to provide communications resources of the wireless access interface on the uplink for the communications device to transmit data to the infrastructure equipment or on the downlink for the communications device to receive data from the infrastructure equipment, to receive an indication (430, 454) on a downlink of the wireless access interface of one of the plurality of different subcarrier spacing which the communications device should use to transmit or to receive the signals representing the data, the indicated subcarrier spacing also determining whether the communications device should use a single subcarrier or multiple subcarriers.