The present disclosure relates to a communication technique of fusing a 5G communication system for supporting higher data transmission rate beyond a 4G system with an IoT technology and a system thereof, and provides an intelligent service based on the 5G communication technology and the IoT related technology. A method of a terminal in a wireless communication system includes receiving, from an AMF, a first message including first information for identifying the AMF, the first information being assigned upon a successful registration to a first access; determining whether a second access is located in a same PLMN of the first access; and transmitting, to an access network entity of the second access, a second message requesting registration to the second access and including second information for identifying the AMF, in case that the second access is located in the same PLMN of the first access.