Techniques are described for wireless communication. One method includes determining, based at least in part on a number of downlink component carriers (CCs) scheduled for a user equipment (UE) during a reporting interval, a number of bits to be included in a physical uplink control channel (PUCCH) acknowledgement/non-acknowledgement (ACK/NAK) payload for the reporting interval; and selecting, based at least in part on the determined number of bits, a format of the PUCCH ACK/NAK payload.