A method performed by a base station in a wireless communication system is provided. The method includes transmitting, by a control plane (CP) of a centralized unit (CU) of the base station, a bearer context modification request message to a user plane (UP) of the CU of the base station, wherein the bearer context modification request message includes information associated with a request for a packet data convergence protocol (PDCP) sequence number (SN) status, and transmitting, by the UP of the CU of the base station, based on the bearer context modification request message, a bearer context modification response message to the CP of the CU of the base station, wherein the bearer context modification response message includes information associated with the PDCP SN status and information associated with at least one QoS flow, of which a service data adaptation protocol (SDAP) end marker is not received by the UP of the CU.