Method for transmitting and receiving signal related to switching access in wireless communication system, and device therefor

An apparatus for a registration procedure related to switching of 3rd Generation Partnership Project (3GPP) access from Evolved Packet System (EPS) to 5th Generation System (5GS) in a wireless communication system, the apparatus comprising:

• a memory;
• and
• at least one processor coupled to the memory,
• wherein the at least one processor is configured to control a second Access and Mobility Management Function (AMF) to:
• receive, from a User Equipment (UE), a registration request message including a first 5G-Globally Unique Temporary Identifier (5G-GUTI) allocated by a first AMF, and
• transmit, to the UE, a message related to a registration acceptance, the message including a second 5G-GUTI,
• wherein the registration request message is received by the second AMF based on the switching of the 3GPP access of the UE from the EPS to the 5GS,
• wherein the first 5G-GUTI includes identification (ID) information of the first AMF serving the non-3GPP access of the UE, and
• wherein the second 5G-GUTI is related to the second AMF serving both of the non-3GPP access and the 3GPP access of the UE.