A user device includes a receiving unit configured to receive first information and second information from a base station device, the first information indicating one or more bands that are candidates for a band combination to be supported, the second information indicating which RAT (Radio Access Technology) is to be used; a control unit configured to determine, based on the second information, the band combination to be supported from among the one or more bands included in the first information; and a transmitting unit configured to transmit, to the base station device, is terminal capability information including the determined band combination.