Under GST e-invoicing, businesses that are notified for it report their B2B invoices to a government Invoice Registration Portal (IRP). The IRP validates the invoice and returns an Invoice Reference Number (IRN) and a signed QR code, which are printed on the invoice.
Who has to e-invoice
E-invoicing applies to businesses whose turnover crosses the limit notified by the government, and to specific kinds of documents. The limit has been lowered over time, so check the current notification, or ask your tax adviser, to confirm whether and from when it applies to you.
How an invoice gets its IRN
- You prepare the invoice in your billing or ERP software as usual.
- The invoice data is sent to the IRP in the prescribed format, directly or through a GST Suvidha Provider (GSP).
- The IRP validates it and returns the IRN, an acknowledgement number and date, and a signed QR code.
- The IRN and QR code are added to the invoice you give the customer.
Changing an e-invoiced invoice
Once registered, an invoice should not be edited in your books. An IRN can be cancelled only within the time window the IRP allows; after that, corrections are made with credit or debit notes, which may themselves need to be reported.
Why GSPs exist
A GSP provides a connection between business software and the government systems, so software does not have to connect to each one directly. You hold an account with the GSP, and your software uses its credentials.
General information about GST processes, last reviewed on 7 October 2026. Rules, limits and due dates change by notification; this is not tax advice. Confirm what applies to your business with your tax adviser.