From a regulatory perspective, as 5G networks are going to all-IP, it may be appropriate to consider alternatives to the use of SIM, E164 (international public telecommunication numbering plan) and Type Allocation Code (TAC), which uniquely identifies each mobile device’s model number and version. For example, is IMEI still the way to capture the right device for legal interception, or should a new approach be taken? TAC (a subset of the IMEI), was developed to uniquely identify a wireless device. However, it is now found that it may not be appropriate anymore for an operator to identify a specific version of a model number. In the case if SIMs, should it be further improved or a new approach taken, although use of IP certificate may not be an improvement?