The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Methods and systems for handling network slice admission control for User Equipment (UE) are provided. The disclosure relates to network slicing and more particularly, to a system and method of ensuring that a communication system is able to accurately enforce quota on the maximum number of UEs concurrently registering for a network slice defined by a Single Network Slice Selection Assistance Information (S-NSSAI). The disclosure describes how the limits of “Number of Terminals” configured for an S-NSSAI may be accurately maintained in a Network Slice Admission Control Function (NSACF), and thus the enforcement may be performed when the limit is really exhausted. The disclosure also describes that a deregistration notification from a Unified Data Management (UDM) may act as a trigger for an old Mobility Management Function (AMF) to decrement counts in the NSACF as the old AMF is no longer serving the UE.