3. Under GST law, an Input Service Distributor (ISD) registration cannot discharge liability under Reverse Charge Mechanism (RCM). In cases where services such as security services are received and are liable to GST under RCM, the tax must be paid by a regular GST registration and not through the ISD GSTIN. Since an ISD registration is only meant for distribution of input tax credit (ITC) and does not file GSTR-3B or maintain an electronic cash ledger for tax payment, it is legally not permitted to pay RCM liability. Accordingly, the regular GST registration of the company should discharge the RCM liability in cash through the electronic cash ledger, report the same in GSTR-3B, and thereafter avail eligible ITC subject to Section 16 conditions of the CGST Act. Once the ITC is validly availed by the regular registration, the same may be distributed to other units through the ISD mechanism by issuing ISD invoices in accordance with Rule 39 of the CGST Rules, wherever the input services pertain to multiple branches or registrations. Thus, the correct legal sequence is: payment of RCM by the regular GST registration availment of ITC distribution of credit through ISD, if eligible. This position has been affirmed by the Karnataka High Court in M/s. Micro Labs Limited vs Joint Commissioner of Central GST, wherein the Court held that an ISD registration is merely a mechanism for distribution of credit and cannot be treated as a taxable person for payment of RCM liability.