Disclosed are a method and an apparatus for transmitting and receiving data. A method for transmitting an uplink comprises the steps of: a terminal receiving first downlink data from a first cell through a first subframe; the terminal receiving second downlink data from a second cell through the first subframe; the terminal transmitting first uplink data, which is generated based on a first identifier of the first cell, as a reply to the first downlink data through a second subframe, and the terminal transmitting second uplink data, which is generated based on a second identifier of a second cell, as a reply to the second downlink data through the second subframe.