IRN and the signed QR code
The reference number the portal issues, and the QR that proves the invoice is real.
Last checked 20 September 2026
The IRN is a 64-character hash the Invoice Registration Portal generates for each reported invoice, making it unique across India. The QR code is the portal’s digitally signed summary of that invoice, printed on the bill so anyone can verify it is genuine without contacting you.
What the IRN is
The Invoice Reference Number is a hash computed from your GSTIN, the document type, the document number and the financial year. Two consequences follow from that construction:
- The same invoice cannot be reported twice — the portal recognises the repeat and rejects it.
- The IRN is derived, not allocated. It is not a sequence and it carries no meaning you can read.
Your own invoice number is unaffected. The IRN sits alongside it.
What the QR code contains
The signed QR carries a summary of the invoice, signed by the portal — typically the supplier and buyer GSTINs, the invoice number and date, the value, the number of line items, the main HSN, and the IRN itself.
Because it is signed, it cannot be altered without breaking the signature. Anyone with a reader can confirm that this invoice was genuinely reported, with these values, by this supplier. That is the point of it: verification without a phone call.
Not the same as a payment QR
An e-invoice QR proves the invoice is registered. A UPI QR lets someone pay you. They look alike and do completely different jobs — a bill can carry both. See printing a UPI QR on invoices.
What must be printed
The invoice given to the buyer has to carry the IRN and the signed QR code. The QR must be legible and large enough to scan — a compressed, faint or clipped code on a thermal roll is a practical failure even when the data behind it is correct.
Cancelling
| When | What you can do |
|---|---|
| Within 24 hours of reporting | Cancel the IRN on the portal. Cancellation is whole-invoice — you cannot amend part of it |
| After 24 hours | The IRN stands. Adjust with a credit or debit note |
A cancelled IRN does not free the invoice number for reuse. Do not report a fresh invoice with the same number — see invoice numbering rules.
The reporting time limit
Larger taxpayers cannot report invoices indefinitely after the event. A limit of 30 days from the document date has applied, extended down to businesses with aggregate turnover of ₹10 crore and above from 1 April 2025. Report late and the portal simply refuses the document.
Which makes a stuck invoice an urgent problem
Before the limit, an unreported invoice was untidy. Now it has a deadline. Whatever system you use should show you what has not been reported, without you having to go looking.
Can I write the IRN by hand if the print is bad?
The IRN is 64 characters. In practice, reprint the invoice.
Does the buyer need to do anything with the QR?
Not necessarily, but many verify it, and the reported data reaches their statements automatically. See GSTR-2B reconciliation.
What if I reported the wrong values?
Within 24 hours, cancel and report again. After that, a credit or debit note is the route — and both are themselves reportable.
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