GST IRN India Explained: Scope, Threshold History, Input Tax Credit, and the 2026 Timeline

India's GST e-invoicing regime requires every in-scope B2B invoice to be registered with an Invoice Registration Portal (IRP) and assigned a 64-character IRN before it is legally valid for input tax credit. The threshold has stepped down progressively from ₹500 crore (October 2020) to ₹5 crore (August 2023), making it one of the most aggressively expanded clearance mandates in the world. The IRP returns a signed JWT QR alongside the IRN — both must appear on the buyer-facing invoice as the basis for the buyer's ITC claim, with a 24-hour cancellation window, a 30-day upload limit for AATO above ₹10 crore, and mandatory 2FA on every IRP-linked GSTN account.

What GST IRN actually is

The Invoice Reference Number (IRN) is a 64-character SHA-256 hash generated by the IRP from the GST INV-01 JSON payload submitted by the seller.

The Invoice Reference Number (IRN) is a 64-character SHA-256 hash generated by the IRP from the GST INV-01 JSON payload submitted by the seller. The hash combines the seller GSTIN, the invoice number, the financial year, and the document type, so the IRN is deterministic for a given invoice — re-submitting the same payload produces the same IRN, which is how duplicate-detection works.

Alongside the IRN the IRP returns a signed JWT QR. The JWT payload contains the IRN, seller and buyer GSTINs, document type, invoice value, total tax, and the signing certificate metadata. The buyer's AP system decodes the JWT, verifies the IRP signature, and treats the result as proof that the seller actually cleared the invoice with the GST authority. Without the JWT QR — or with one that fails signature verification — the buyer cannot reliably claim ITC.

Who must comply today

Above ₹5 crore aggregate annual turnover (AATO)

Mandatory since 1 August 2023 per CBIC Notification 10/2023-Central Tax. The test is whether AATO crossed ₹5 crore in any financial year from 2017-18 onwards; once you cross, you remain in scope even if turnover later drops back below the threshold.

B2C invoices

Not currently in scope. The GST Council has signalled B2C extensions in successive meetings but no implementation date has been confirmed as of late 2026. When B2C joins, the architecture will most likely follow the existing IRP path with additional fields for unregistered buyers.

Exports and SEZ supplies

In scope on the same ₹5 crore threshold as domestic B2B. The INV-01 schema distinguishes between export with payment of IGST, export without payment of IGST, SEZ with payment of IGST, and SEZ without payment of IGST.

Notified exempted categories

Insurance companies, banking and NBFC services, GTA (goods transport agencies), passenger transport, and some other categories are exempted by CBIC notification regardless of turnover. Government departments and local authorities are also outside the regime.

Threshold history: the step-down from ₹500 crore to ₹5 crore

The Indian GST e-invoicing regime is unusual for how aggressively the threshold has been pulled down since launch:

The Indian GST e-invoicing regime is unusual for how aggressively the threshold has been pulled down since launch:

The CBIC publishes notifications when the threshold drops further. Market expectations point to ₹1–2 crore as the next step, but no formal notification has been issued as of late 2026.

Why the signed JWT QR matters for ITC

The signed QR is a JSON Web Token (RFC 7519) signed by the IRP's RSA key.

The signed QR is a JSON Web Token (RFC 7519) signed by the IRP's RSA key. The QR payload encodes:

• The IRN.
• Seller and buyer GSTINs.
• Document type, document number, document date.
• Total invoice value and total GST.
• Main HSN code.
• Signing certificate metadata and the IRP digital signature.

The buyer's AP system decodes the QR, verifies the signature against the published IRP certificate, and confirms the seller cleared the invoice. This is the basis on which the buyer claims input tax credit. The seller can claim "I issued the invoice" all day long — but if the QR does not exist, or if the signature fails, ITC is denied at the buyer's audit.

What the payload must contain

Seller GSTIN, legal name, address, place of business, state code. Buyer GSTIN (or "URP" for unregistered persons), with place of supply driving CGST/SGST vs IGST routing.

• Seller GSTIN, legal name, address, place of business, state code.
• Buyer GSTIN (or "URP" for unregistered persons), with place of supply driving CGST/SGST vs IGST routing.
• Document type (INV for invoice, CRN for credit note, DBN for debit note).
• Line items with HSN (goods) or SAC (services) codes — 8-digit HSN mandatory for AATO > ₹5 crore.
• The GST breakdown — CGST + SGST for intra-state, IGST for inter-state and exports.
• Document totals reconciling to the line-item totals at the paise level.

Cancellation, amendment, and the 30-day upload limit

The cleared invoice lifecycle has three timing rules:

The cleared invoice lifecycle has three timing rules:

• 24-hour cancellation: the seller can cancel an IRN within 24 hours via the IRP. After 24 hours, the IRN is final.
• 30-day upload limit: for taxpayers with AATO above ₹10 crore, the IRP refuses payloads with an invoice date more than 30 days old. This rule was originally piloted for AATO > ₹100 crore and progressively lowered.
• Amendments via credit/debit notes: after the 24-hour cancellation window, corrections require a credit note (CRN) or debit note (DBN) that gets its own IRN and references the original. There is no editing of a cleared invoice.

Cleared IRNs auto-populate the seller's GSTR-1 return; the seller confirms the data rather than re-keying it.

How GST IRN compares to ZATCA, MyInvois, and FIRS MBS

For the full architectural comparison see clearance vs reporting models in e-invoicing.

For the full architectural comparison see clearance vs reporting models in e-invoicing.

Rollout timeline and what changes through 2026

Rollout timeline and what changes through 2026 includes: Threshold: ₹5 crore in place since 1 August 2023; market expects ₹1–2 crore as the next step, no formal notification as of November 2026. 30-day upload limit: currently AATO > ₹10 crore; expansion to AATO > ₹5 crore widely anticipated.

• Threshold: ₹5 crore in place since 1 August 2023; market expects ₹1–2 crore as the next step, no formal notification as of November 2026.
• 30-day upload limit: currently AATO > ₹10 crore; expansion to AATO > ₹5 crore widely anticipated.
• 2FA: fully enforced across the IRP-linked taxpayer base.
• B2C extension: signalled by the GST Council; no notification yet.
• e-Way Bill integration: the IRN auto-generates the e-Way Bill when transport details are provided, removing the double-keying problem.
• GSTR-1 auto-population: mature; the seller confirms rather than re-keys.

Key takeaways

Key takeaways includes: GST IRN is clearance — no IRN, no ITC for the buyer, no working capital for the seller. The signed JWT QR is the buyer's verification artefact; the seller's claim alone does not unlock ITC.

• GST IRN is clearance — no IRN, no ITC for the buyer, no working capital for the seller.
• The signed JWT QR is the buyer's verification artefact; the seller's claim alone does not unlock ITC.
• The threshold has dropped six times in three years; assume it keeps falling.
• The 30-day upload limit (AATO > ₹10 crore) and 24-hour cancellation window are both audited.
• 2FA is non-negotiable on every IRP-linked GSTN account.

Related reading

For the implementation playbook, read how to comply with GST IRN in India. The original launch primer lives in e-invoicing in India with GST.

For the implementation playbook, read how to comply with GST IRN in India. The original launch primer lives in e-invoicing in India with GST. To compare across regimes, read clearance vs reporting models and real-time invoice reporting. For the artefact details, see what is an IRN and QR codes on tax invoices.

Authority sources

• GSTN — e-Invoice portal
• GSTN — e-Invoice FAQs and approved IRP list
• CBIC GST — notifications and threshold history
• NIC IRP API Sandbox
• NIC e-Invoice + e-Way Bill technical documentation