Disclosed is a terminal apparatus in which: a decoding section (210) that stores, in a retransmission buffer, downlink data transmitted by each of the plurality of component carriers and decodes the downlink data; and a radio transmitting section (222) that transmits, using a first component carrier of the plurality of component carriers, a response signal for first downlink data received using the first component carrier and a response signal for second downlink data received using a second component carrier of the plurality of component carriers. In addition, a second buffer is divided into regions respectively corresponding to retransmission processes based on a specific value determined by a combination of a first configuration pattern that is set in the first component carrier and a second configuration pattern that is set in the second component carrier.