User equipment includes a transmitter configured to transmit a random access preamble or an identifier of the user equipment to a base station apparatus in a two-step random access procedure, a receiver configured to receive a response signal corresponding to at least one of the random access preamble and the identifier of the user equipment, and a downlink signal based on the response signal, from the base station apparatus, and a control unit configured to determine that a contention resolution is successful when information included in the downlink signal matches a part of or all of the identifier of the user equipment.