A method and a system for supporting flexible user equipment (UE) bandwidth by the UE during a random access are provided. The method includes transmitting, to a base station, a random access preamble over a first bandwidth selected among a plurality of channel bandwidths of the UE, receiving, from the base station, a random access response over a second bandwidth selected among the plurality of channel bandwidths, and transmitting, to the base station, a scheduled transmission message over a third bandwidth selected among the plurality of channel bandwidths of the UE.