A terminal apparatus includes: a reception unit configured to: receive a PDCCH or an EPDCCH with a DCI format and a first RRC parameter, and decode a PDSCH according to detection of the PDCCH or the EPDCCH; and a transmission unit configured to: transmit a HARQ-ACK in a subframe n according to detection of the PDSCH in a subframe n−k. Whether the PUCCH resource is given at least based on the first RRC parameter is determined at least based on part of or all of the first condition and the second condition described below: first condition: the value k, and second condition: which one of CSS and USS is a search space to which a physical downlink control channel including the DCI format is mapped.