GST Input Service Distributor (ISD) Compliance

Input Service Distributor (ISD) compliance is governed by Section 2(61) (definition) and Section 20 (manner of distribution of credit) of the CGST Act, 2017, read with Rule 39 of the CGST Rules, 2017, as substituted by Notification No. 12/2024-Central Tax.

Historically, ISD registration was optional, and a head office could instead "cross-charge" common input services received centrally to other GSTINs registered under the same PAN. The Finance (No. 1) Act, 2024 amended Sections 2(61) and 20 of the CGST Act to make separate ISD registration mandatory, with effect from 1 April 2025, for any office of a registered person that receives tax invoices for input services — including services taxable under reverse charge, per the amended Section 20 — which are common to, and meant for distribution among, two or more distinct persons (GSTINs) registered under the same PAN.

Under the substituted Rule 39, an ISD must:

• Distribute eligible and ineligible input tax credit separately, in the same month in which the credit is available, to the recipient units to which the underlying service is attributable.


• Distribute credit relating to more than one recipient unit in proportion to the turnover of each such unit in the relevant period, as prescribed under Rule 39(1)(d).


• Issue a tax invoice, termed an "ISD invoice," to each recipient unit prior to distribution, clearly indicating the credit being distributed and the amount.


• File a monthly return in FORM GSTR-6, by the 13th of the month following the tax period — the document through which the distributed credit reaches the recipient units' GSTR-2B and electronic credit ledger.

Because the ISD mechanism became the sole statutorily permitted route (in place of cross-charge) for distributing such common credit from 1 April 2025, a recipient unit that claims credit which should have flowed through an ISD, but did not, is exposed to reversal of that credit and demand proceedings under Section 73 or Section 74A of the CGST Act for wrongly availed input tax credit.

An Input Service Distributor (ISD) is the registered office of a business with multiple registrations that receives input services centrally and distributes the input tax credit on them to its units. Under Section 20 of the CGST Act 2017 and Rule 39 of the CGST Rules, the ISD must distribute the credit to the units in proportion to their turnover — using the credit of the input services as distributed, with the distribution reflected in the ISD's own return, GSTR-6, and in the credit of the receiving units. The ISD is how a multi-location business keeps its credit where the liability is.

The ISD is the plumbing of group credit. A business with a central office and state units receives services — telecom, software, professional fees — at the head office, and the credit on them belongs with the units that use the services. The ISD mechanism moves the credit legally, in proportion to turnover, so that each unit's GST liability is matched by the credit it is entitled to use.

The cost of a missing or misused ISD is the blocked or wrong credit: without the ISD registration the head-office credit cannot lawfully flow to the units, and with a faulty distribution the units claim credit they are not entitled to, building a reversal with interest at audit. The distribution must follow Section 20's proportionate basis and the prescribed manner of Rule 39.

This service is for multi-location businesses with a centralised service billing. We set up the ISD registration, map the input services and the receiving units, compute the proportionate distribution under Section 20 and Rule 39, file the GSTR-6, and reconcile the distributed credit with the units' ledgers so the group's credit position is clean.