Input Service Distributor (ISD)

What Is an Input Service Distributor (ISD)?

An Input Service Distributor (ISD) is a GST-registered office of a business that receives tax invoices for input services procured centrally — audit fees, software licences, group insurance, legal advisory, head-office rent — and passes on the credit of the tax paid on those services to the business's other GST registrations that actually use the services. Section 2(61) of the Central Goods and Services Tax (CGST) Act, 2017 was rewritten by section 11 of the Finance Act, 2024 and now defines an ISD as "an office of the supplier of goods or services or both which receives tax invoices towards the receipt of input services, including invoices in respect of services liable to tax under sub-section (3) or sub-section (4) of section 9 of this Act or under sub-section (3) or sub-section (4) of section 5 of the Integrated Goods and Services Tax Act, 2017, for or on behalf of distinct persons referred to in section 25, and liable to distribute the input tax credit in respect of such invoices in the manner provided in section 20." The words bringing in reverse-charge credit under the IGST Act were added by section 121 of the Finance Act, 2025. The older definition, which turned on invoices "issued under section 31" and on the recipients sharing the ISD's Permanent Account Number, no longer applies.

In plain terms: ISD is the plumbing that lets input tax credit flow to where it is actually needed. A company with one head-office GSTIN and several branch GSTINs across states often pays for shared services centrally, at the head office. Without the ISD mechanism, that credit would sit stranded at the head office — which may have little or no output tax liability of its own — while the branches that generate revenue and output tax have no credit to set off against it.

Legal Basis

• Section 2(61) of the CGST Act, 2017 — defines Input Service Distributor.
• Section 20 of the CGST Act, 2017 — "Manner of distribution of credit by Input Service Distributor," substituted in full by section 12 of the Finance Act, 2024 with effect from 1 April 2025. It now makes ISD registration compulsory and leaves the pro-rata mechanics to the rules.
• Section 24(viii) of the CGST Act, 2017 — lists "Input Service Distributor, whether or not separately registered under this Act" among the categories of persons required to obtain compulsory GST registration, regardless of turnover.
• Section 39(4) of the CGST Act, 2017 — requires every person registered as an ISD to furnish its return "within thirteen days after the end of such month."
• Rule 39 of the CGST Rules, 2017 — the detailed procedure for distributing credit, including the turnover formula and the invoice/credit-note mechanics.
• Rule 54(1) and Rule 54(1A) of the CGST Rules, 2017 — the contents of the ISD invoice and ISD credit note, and of the invoice a same-State registered person issues to pass reverse-charge credit on a common input service to the ISD.
• Rule 65 of the CGST Rules, 2017 — the return-filing mechanics for Form GSTR-6.

How the Distribution Mechanism Works

The current Section 20 does three things. Section 20(1) makes the registration compulsory: any office that receives tax invoices for input services, including invoices for services taxed under reverse charge, "for or on behalf of distinct persons referred to in section 25" shall be required to be registered as an ISD under Section 24(viii) and shall distribute the credit on those invoices. Section 20(2) requires the ISD to distribute the credit of central tax or integrated tax on those invoices, including reverse-charge tax paid by a distinct person registered in the same State as the ISD, in the manner and within the time prescribed by the rules. Section 20(3) allows central tax to be distributed as central tax or integrated tax, and integrated tax as integrated tax or central tax, by issuing a document containing the amount of credit.

The pro-rata conditions that used to sit in Section 20(2) now live entirely in Rule 39, which was substituted by Notification No. 12/2024-Central Tax dated 10 July 2024 and took effect on 1 April 2025, the date appointed by Notification No. 09/2025-Central Tax dated 11 February 2025. Rule 39(1) sets the conditions:

• Credit available for distribution in a month must be distributed in that month, with the details furnished in Form GSTR-6 (clause (a)), and the amount distributed cannot exceed the credit available (clause (b)).
• Credit attributable to a single recipient goes only to that recipient (clause (c)).
• Credit attributable to more than one recipient, or to all of them, is distributed pro rata on the basis of each recipient's turnover in its State or Union territory during the "relevant period," against the aggregate turnover of all such recipients that are operational in the current year (clauses (d) and (e)).
• The "relevant period," defined in the Explanation to Rule 39 rather than in Section 20, is the preceding financial year if the recipients had turnover in it; if not, the last quarter for which turnover figures for all the recipients are available before the month of distribution.

Rule 39(1)(f) puts that split into an exact formula. For a recipient "R1," the credit distributed, "C1," is:

C1 = (t1 ÷ T) × C

where "C" is the total credit available for distribution, "t1" is R1's turnover during the relevant period, and "T" is the aggregate turnover of all recipients to whom the input service is attributable. Two further conditions sit alongside it. Under Rule 39(1)(g), ineligible credit — ineligible under Section 17(5), which blocks credit on items such as motor vehicles for personal use or club memberships, "or otherwise" — must be distributed separately from eligible credit. Under Rule 39(1)(h), central tax, State tax, Union territory tax and integrated tax must each be distributed separately.

Same-State vs. Cross-State Recipients

Rule 39(1)(j) draws a critical distinction based on geography. If the recipient GSTIN is located in the same State or Union territory as the ISD, the credit is distributed as central tax and State/UT tax, respectively. If the recipient is in a different State or Union territory, the central-tax-plus-State-tax credit must instead be distributed as integrated tax (IGST) — the ISD effectively converts local tax credit into IGST credit so it can cross state lines. Credit already held as IGST is always distributed as IGST to every recipient, regardless of location, under Rule 39(1)(i).

Registration, Invoicing and Returns

An ISD registration is separate from — and additional to — any regular GST registration the same PAN-holder may have at that location. Section 24(viii) places ISD in the list of persons for whom registration is compulsory irrespective of the turnover threshold that otherwise governs GST registration. In practice, a company designates one office (usually the head office or a regional office) as the ISD and obtains a distinct GSTIN for it, used only to receive input-service invoices and issue distribution documents — an ISD does not undertake any outward taxable supply itself.

Under Rule 39(1)(k) and (l), the ISD issues two kinds of documents to move credit: an ISD invoice, in the form set out in Rule 54(1) and clearly marked as issued only for distribution of credit, and an ISD credit note, also under Rule 54(1), used to reduce credit already distributed when the amount changes for any reason — for example, if the supplier of the input service later issues a credit note to the ISD.

The ISD's monthly return is Form GSTR-6. Under Rule 65, the ISD prepares it from the auto-populated Form GSTR-6A (which pulls in the supplier-reported invoices), adding, correcting, or deleting entries as needed, and reports both the credit received and the credit distributed. Section 39(4) fixes the filing deadline at thirteen days after the end of the return month — commonly referred to as "by the 13th." Unlike most other GST returns, GSTR-6 has no turnover-based exemption or quarterly option; every registered ISD files it monthly.

Why This Matters for a Foreign Company Operating in India

Foreign investors setting up in India rarely operate through a single GSTIN. A subsidiary with a manufacturing unit in one State and a sales or warehousing presence in another will hold separate GST registrations for each — GST registration in India is State-wise, not PAN-wise. Group-level contracts, however — the statutory audit, the ERP or software licence, the parent-company management fee, group insurance, legal counsel retained centrally — are typically invoiced to one location. If that location cannot pass the credit on to the GSTINs actually generating output tax, the group's overall GST cost rises, because credit sits unused at one registration while cash is paid out at others.

Structuring an ISD from the outset — rather than retrofitting it after an internal or statutory audit flags the mismatch — also avoids disputes over whether internal cross-charges between the company's own branches (a separate concept, taxed as a deemed supply between "distinct persons" under Schedule I where the ISD route is not used) have been correctly valued and taxed. Getting the ISD registration and Rule 39 turnover ratios right from the first month of multi-state operations is materially simpler than reconstructing distribution ratios and issuing corrective ISD credit notes for prior periods.

Worked Example

Nordholm Technologies Pvt Ltd, a foreign-owned Indian subsidiary, has its head office and ISD registration in Maharashtra, with branch GSTINs in Karnataka and Tamil Nadu. In a given month, the head office pays a group statutory audit fee and incurs CGST + SGST of INR 10,00,000 on the invoice. Karnataka's branch turnover in the relevant period is INR 6 crore and Tamil Nadu's is INR 4 crore (T = INR 10 crore).

• Karnataka's share: C1 = (6 crore ÷ 10 crore) × 10,00,000 = INR 6,00,000
• Tamil Nadu's share: C1 = (4 crore ÷ 10 crore) × 10,00,000 = INR 4,00,000

Because both recipients are outside Maharashtra (the ISD's own State), Rule 39(1)(j)(ii) requires the head office to distribute both shares as IGST, not as CGST/SGST — even though the original invoice carried CGST and SGST. The ISD reports the inward credit received and the two IGST distributions in that month's Form GSTR-6, filed by the 13th of the following month.

Common Mistakes

• Not obtaining a separate ISD registration. Distributing credit informally through internal debit notes, without an ISD GSTIN and Form GSTR-6 filings, does not satisfy Section 20 and exposes the recipient GSTINs to credit denial on audit. Since 1 April 2025 the registration is not optional for an office that receives such invoices on behalf of distinct persons.
• Distributing CGST/SGST credit across State lines without converting to IGST. Rule 39(1)(j)(ii) is frequently missed by finance teams applying a single blended ratio without checking each recipient's location relative to the ISD.
• Mixing eligible and ineligible credit. Section 17(5)-blocked credit (for example, credit on certain motor vehicles or employee-related expenses) must be identified and distributed separately as ineligible credit, not silently excluded or bundled in.
• Using the wrong "relevant period" turnover. New branches with no turnover in the preceding financial year must be assessed under the last-available-quarter rule in the Explanation to Rule 39, not the full-year figures used for established branches.
• Routing reverse-charge credit incorrectly. Common input services taxed under the reverse charge mechanism are now expressly within the ISD's remit, but the ISD does not pay that tax itself. Under Rule 39(1A), a registered person holding the same PAN and State code as the ISD pays the tax and issues an invoice, or a credit or debit note, in the form set out in Rule 54(1A), to transfer the credit of that common input service to the ISD, which then distributes it under Rule 39(1). Section 20(2) matches this, covering reverse-charge tax "paid by a distinct person registered in the same State as the said Input Service Distributor."

Frequently Asked Questions

Does every company with multiple GST registrations need an ISD?

Since 1 April 2025, yes, wherever an office receives tax invoices for input services on behalf of the company's other registrations. Section 20(1) says such an office shall be required to be registered as an ISD under Section 24(viii), so it is no longer a choice the company can decline. A company with a single GST registration, or one where every input service is invoiced and used within that one registration, has nothing to distribute and needs no ISD.

Is ISD the same as cross-charge between branches?

No. ISD distributes credit on input services bought from third-party suppliers. Cross-charge is a separate concept: when one branch of a company performs services for another branch (for example, a head office providing shared management or IT support to its own branches), that internal supply between "distinct persons" under Schedule I of the CGST Act is itself a taxable supply, valued and invoiced independently of the ISD mechanism.

What happens if the ISD distributes more credit than a recipient is entitled to?

Rule 39(1)(n), applied through Rule 39(2), requires the excess to be corrected through an ISD credit note in the month it is identified. The over-distributed amount is either reduced from that month's distribution or, if the distribution is otherwise too small to absorb the reduction, added to the recipient's own output tax liability.

Can an ISD registration also make outward taxable supplies?

An ISD registration is intended solely to receive input-service invoices and distribute credit — it is not meant to be used for making outward taxable supplies of goods or services. Businesses typically keep the ISD GSTIN administratively separate from any regular GSTIN the same office may hold for its own trading activity.

What return does an ISD file, and when is it due?

An ISD files Form GSTR-6 every calendar month, reporting the credit it received and the credit it distributed to each recipient. Section 39(4) of the CGST Act fixes the deadline at thirteen days after the end of the month, with no quarterly or turnover-based exemption.

See also: Input Tax Credit, Goods and Services Tax, and GST Registration.

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