The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. 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.