# What Is an Input Service Distributor (ISD) Under GST? **Category:** GST | **Published:** 2026-06-26 | **Last reviewed:** 2026-06-26 | **Author:** Mrs. Swapna Patel An Input Service Distributor (ISD) is an office of a business that receives tax invoices for input services used across several branches under the same PAN, and distributes that input tax credit (ITC) to those branches. It is defined in Section 2(61) and governed by Section 20 of the CGST Act. From 1 April 2025, registering as an ISD became mandatory wherever common input services, including services taxed under reverse charge, are received for distinct GST registrations under one PAN. The ISD takes a separate registration under Section 24(viii), issues ISD invoices, distributes credit pro-rata to each branch turnover under Rule 39, and files a monthly GSTR-6 return. ISD handles input services only, not goods or capital goods. > **Myth:** A head office can claim the GST on a company-wide software or audit bill and use that credit at any branch it likes. > > **Fact:** From 1 April 2025, common input-service credit must be passed down through a registered Input Service Distributor under [Section 20 of the CGST Act](https://www.cbic.gov.in/htdocs-cbec/gst/cgst-act), made mandatory by [Notification 16/2024-Central Tax](https://cbic-gst.gov.in/central-tax-notfns-2024.html). ## What is an Input Service Distributor (ISD)? > **Short answer:** An ISD is an office of a business that receives invoices for [input services](/answers/what-is-input-tax-credit-itc) used by multiple branches under the same PAN, and distributes that credit to them, defined in [Section 2(61) of the CGST Act](https://www.cbic.gov.in/htdocs-cbec/gst/cgst-act). Large companies often buy services centrally: a single audit, insurance, or software subscription billed to the head office but used by branches across states. The GST on that bill sits at one location, yet the benefit belongs to many. The ISD mechanism lets the head office pass that input tax credit down to each branch, instead of stranding it in one place. It covers input services only, never goods or capital goods. ## Why did ISD registration become mandatory from 1 April 2025? > **Short answer:** Because [Section 20](https://www.cbic.gov.in/htdocs-cbec/gst/cgst-act) was amended to read that an ISD "shall distribute" common credit, with effect from 1 April 2025 under [Notification 16/2024-Central Tax](https://cbic-gst.gov.in/central-tax-notfns-2024.html). - Before this date, using an ISD was optional and many groups claimed the full credit at one GSTIN, which distorted state revenue. - A business that receives common input services for two or more GST registrations under one PAN must now take a separate ISD registration under Section 24(viii). - The amended rule also pulls in services taxed under reverse charge (Sections 9(3) and 9(4)), so those credits must travel through the ISD too. ## How is the credit split between branches? > **Short answer:** Pro-rata to each branch turnover under [Rule 39 of the CGST Rules](https://www.cbic.gov.in/htdocs-cbec/gst/cgst-rules-as-amended): a branch with a larger share of turnover receives a larger share of the credit. - Credit attributable to one branch goes wholly to that branch; common credit is shared across all on a turnover basis. - IGST credit is distributed as IGST; CGST and SGST credit is distributed by whether the receiving branch is in the same state. - The ISD reports the distribution in a monthly GSTR-6 return, and each branch then sees the credit in its own account. ## How does an ISD invoice differ from a normal GST invoice? > **Short answer:** An ISD issues an ISD invoice only to pass on credit, not to charge for a supply, so it shows no taxable sale, unlike a regular [tax invoice](/answers/what-is-a-pakka-bill). - A normal tax invoice records a sale and the GST charged on it; an ISD invoice records only credit being handed to a branch. - Getting this wrong matters: credit distributed in excess can be recovered from the branch with interest under Section 21. - For your actual sales, you still issue a standard GST tax invoice that carries the tax your customer can claim. **[Generate a clean GST tax invoice in 60 seconds](https://hrareceipt.in/pakka-bill)** ## Primary sources - [Section 20, Central Goods and Services Tax Act 2017 — CBIC](https://www.cbic.gov.in/htdocs-cbec/gst/cgst-act) — Manner of distribution of credit by an Input Service Distributor. - [Section 2(61), Central Goods and Services Tax Act 2017 — CBIC](https://www.cbic.gov.in/htdocs-cbec/gst/cgst-act) — Definition of Input Service Distributor. - [Notification 16/2024-Central Tax dated 6 August 2024 — CBIC](https://cbic-gst.gov.in/central-tax-notfns-2024.html) — Appoints 1 April 2025 as the date the amended ISD provisions take effect, making the mechanism mandatory. - [Rule 39, Central Goods and Services Tax Rules 2017 — CBIC](https://www.cbic.gov.in/htdocs-cbec/gst/cgst-rules-as-amended) — Procedure for distribution of input tax credit by an ISD, including the pro-rata turnover formula. ## Related - [What is input tax credit (ITC) — the credit an ISD distributes](https://hrareceipt.in/answers/what-is-input-tax-credit-itc) - [Reverse charge mechanism (RCM) — credits now routed through ISD](https://hrareceipt.in/answers/reverse-charge-mechanism-rcm-gst) - [CGST, SGST and IGST — the three components an ISD splits](https://hrareceipt.in/answers/cgst-sgst-igst-three-gst-components) --- *Source: [What Is an Input Service Distributor (ISD) Under GST?](https://hrareceipt.in/answers/what-is-input-service-distributor-isd-gst) — HRAReceipt.in* *This Markdown mirror is published for AI-crawler ingestion. 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