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.The method includes transmitting a service authorization request message to a first network device, the first network drive including a proximity-based service (ProSe) function, and receiving a service authorization response message from the first network device. The first terminal is a relay terminal capable of performing a UE-to-network relay function.