What is E-Invoice (IRN)?
Last updated: 27 June 2026
E-Invoice (Electronic Invoice) is a system under GST where eligible businesses must upload every B2B invoice to a government-authorised Invoice Registration Portal (IRP), which validates the data and returns a unique Invoice Reference Number (IRN) and QR code — the invoice is legally valid only after receiving this IRN.
An e-invoice is not a PDF sent by email; it is the same invoice the seller already generates, but authenticated in real time by the government portal. The buyer's GSTIN, HSN codes, and tax amounts are validated before the IRN is issued.
Who must generate e-invoices?
E-invoicing is mandatory for any business whose aggregate annual turnover (AATO) exceeded ₹5 crore in any financial year from 2017-18 onward. Businesses below ₹5 crore are currently exempt. Covered documents include B2B invoices, debit notes, credit notes, and export invoices.
Fact box. Businesses with AATO of ₹10 crore or more must report invoices to the IRP within 30 days of the invoice date (effective 1 April 2025). Uploading after 30 days results in rejection — no IRN is generated and the invoice cannot be used for ITC.
How the IRN process works
- Seller generates invoice in their accounting/ERP system.
- Invoice data (JSON, Form GST INV-01 schema version 1.1) is sent to one of the six authorised IRPs.
- IRP validates, deduplicates, digitally signs, and returns the IRN (a 64-character hash), QR code, and signed JSON.
- Seller prints the IRN and QR code on the invoice and sends it to the buyer.
- The invoice data auto-populates the seller's GSTR-1 and the buyer's GSTR-2B — no manual entry needed.
Frequently asked questions
Can I raise an e-invoice after the invoice date? For businesses above ₹10 crore AATO, no — the 30-day window is enforced by the portal. For businesses between ₹5–10 crore, there is currently no enforced time limit, but late reporting affects your buyer's ITC timeline.
Is e-invoicing required for B2C supplies? No. E-invoicing applies only to B2B (buyer has a GSTIN), exports, and notified document types. B2C invoices do not require an IRN but must carry a QR code if turnover exceeds ₹5 crore.
Sources: GSTN e-invoice portal — einvoice.gst.gov.in; CBIC — cbic.gov.in
General information, not professional advice. Verify on the official portal for your case. Reviewed by a Chartered Accountant; last updated 27 June 2026.
Related: GSTIN · E-Way Bill · GSTR-1