A method for obtaining subscriber identifiers using a MAC address range in a 5G system, 5GS, wherein the 5GS comprises a Network Function, NF, Service Consumer, and a functional entity, wherein the functional entity comprises binding information, related to one or more subscribers, stored therein and binding information is composed of binding information elements each comprising: at least one or more subscribers identities; IDs, related to a subscriber; and MAC address assigned to said subscriber; and/or PCF instance IDs, wherein the 5GS further comprises a Unified data management, UDM, a Session Management Function, SMF, and a Policy Control Function, PCF, the method comprising the steps of: querying (S21), from the NF Service Consumer to the functional entity, based on a MAC address range, and zero or more additional query parameters, for all binding information related to all subscribers using said address range which match the query parameters; notifying (S22), from the functional entity to the NF Service Consumer, any binding information that matches the query parameters, wherein the query parameters comprise at least a MAC range and any of the following: a Data Network Name, DNN, Subscription Permanent Identifier, SUPI, Generic Public Subscription Identifier, GPSI, a Single Network Slice Selection Identifier, S-NSSAI, and/or IP domain; receiving (S23), at the NF Service Consumer, the binding information, matching the query parameters, comprising one or more subscriber IDs; querying (S24), from the NF Service Consumer to the UDM, for SMF registration data based on the one or more subscriber IDs, replying (S25), from the UDM to the NF Service Consumer, to the above query, with SMF registration data matching the one or more subscriber IDs, wherein the SMF registration data comprises one or more PDU session IDs and/or SMF instance IDs; receiving (S26), at the NF Service Consumer, the SMF registration data; and interacting (S27), from the NF Service Consumer with the SMF and/or the PCF, using the one or more PDU session IDs and/or SMF instance IDs. querying (S21), from the NF Service Consumer to the functional entity, based on a MAC address range, and zero or more additional query parameters, for all binding information related to all subscribers using said address range which match the query parameters; notifying (S22), from the functional entity to the NF Service Consumer, any binding information that matches the query parameters, wherein the query parameters comprise at least a MAC range and any of the following: a Data Network Name, DNN, Subscription Permanent Identifier, SUPI, Generic Public Subscription Identifier, GPSI, a Single Network Slice Selection Identifier, S-NSSAI, and/or IP domain; receiving (S23), at the NF Service Consumer, the binding information, matching the query parameters, comprising one or more subscriber IDs; querying (S24), from the NF Service Consumer to the UDM, for SMF registration data based on the one or more subscriber IDs, replying (S25), from the UDM to the NF Service Consumer, to the above query, with SMF registration data matching the one or more subscriber IDs, wherein the SMF registration data comprises one or more PDU session IDs and/or SMF instance IDs; receiving (S26), at the NF Service Consumer, the SMF registration data; and interacting (S27), from the NF Service Consumer with the SMF and/or the PCF, using the one or more PDU session IDs and/or SMF instance IDs. <EOS>