Apparatus, computer readable media, and methods are disclosed for sending feedback in a high efficiency service field. An apparatus is disclosed comprising processing circuitry configured to: decode a trigger frame from a second wireless device, wherein the trigger frame indicates a resource allocation for an uplink (UL) multi-user (MU) transmission for the first wireless device. The processing circuitry may be further configured to: determine feedback for a second wireless device based on the resource allocation. The processing circuitry may be further configured to: encode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) to include a high-efficiency (HE) service field comprising the feedback in a physical (PHY) portion of the PPDU. And, the processing circuitry may be further configured to: configure the first wireless device to transmit the PPDU in accordance with the resource allocation to the second wireless device.