What is an invoice reference number?
An invoice reference number is the 64-character hash the Invoice Registration Portal returns when it accepts an invoice a notified supplier has reported. The supplier’s own invoice number is one of the inputs. It is not itself the IRN.
What does the portal return?
The supplier prepares the tax invoice and sends the specified fields to the portal. The portal returns the IRN and a QR code. Both are placed on the invoice the recipient gets. An invoice that the rule says must carry an IRN, and that does not carry one, is not a valid e-invoice. Who has to make that report is on the e-invoice page.
What is the number built from?
The portal builds the hash from the supplier’s GSTIN, the financial year, the document type, and the document number. The invoice value is not one of those four inputs. Two invoices of the same supplier, in the same year, of the same document type, cannot share a document number, because that set is what makes the IRN unique.
Which invoices get one?
A supplier inside the e-invoice rule reports a B2B tax invoice, an export invoice, and an invoice to an SEZ. A credit note and a debit note for a reported invoice are reported as well. A bill to an unregistered consumer is not sent for an IRN. A composition dealer does not e-invoice. The ₹5 crore turnover test, and the classes that stay outside, are on the e-invoice page and are not restated here.
What is not an IRN?
A running serial the accounts software prints for its own filing is not an IRN. A number typed into the invoice without a successful report to the portal is not an IRN. The portal’s response is the record that the number was issued.
Frequently asked questions
Four questions cover a made-up code, the invoice value, a shop bill, and the tax invoice.
Can the supplier type any 64 characters?
No. The Invoice Registration Portal generates the number from the invoice details. A code the billing software invents, without that report, is not an IRN.
Is the invoice value part of the number?
No. The hash uses the supplier’s GSTIN, the financial year, the document type, and the document number. Changing the value does not by itself create a new IRN for the same document number.
Does every shop bill need one?
No. Only a supplier who is inside the e-invoice rule reports the invoices that rule covers. A bill to an unregistered consumer is not reported for an IRN.
Does the number replace the invoice?
No. The supplier still issues the tax invoice. The IRN and the QR code are added after the portal accepts the report.
Sources
The invoice reference number is generated by the Invoice Registration Portal. Who must report an invoice is the e-invoice rule.