How an IRN is generated on a freight forwarding invoice

If your business is above the e-invoicing turnover threshold, a B2B tax invoice is not valid until it has been reported to the Invoice Registration Portal (IRP) and carries an Invoice Reference Number (IRN). For a forwarder, that covers freight, clearance, transport and handling invoices to registered customers, and the credit and debit notes that amend them.

How is an IRN generated?

1. The invoice is converted into the government's e-invoice JSON schema.
2. It is sent to the IRP, either directly through the API or through a GST Suvidha Provider (GSP).
3. The IRP validates it and checks that the document number has not already been reported for that GSTIN and financial year.
4. The IRP returns three things: the IRN (a 64-character hash), an acknowledgement number and date, and a digitally signed QR code.
5. The IRN and QR code then have to appear on the invoice you send.

The same details flow from the IRP into the GST system, which is what fills in your outward supply return.

Why do e-invoices get rejected?

Most rejections come from a few fields:

• A buyer GSTIN that is cancelled or mistyped.
• A state code that does not match the place of supply.
• A missing HSN or SAC code on a line.
• Tax amounts that do not add up to the line values after rounding.
• A document number that was already used, even on an invoice that was later cancelled.

Forwarder invoices add their own complications. One invoice can carry taxable services, pure-agent reimbursements and lines billed in a foreign currency at a stated exchange rate. Each line has to be classified correctly before it goes, because once the IRN is issued the invoice cannot be edited.

An IRN is easy to get and impossible to change. All the care has to happen before you press register.

Can an e-invoice be cancelled or amended?

An e-invoice can be cancelled on the IRP only within 24 hours of generation, and only as a whole. After that, corrections go through credit or debit notes, which are e-invoiced with their own IRN. Larger taxpayers also have a reporting window: invoices older than 30 days can be refused by the IRP. The turnover threshold for that rule has been lowered over time, so check the current notification for your bracket.

Making it routine

The approach that works is to treat registration as the last step of approving an invoice, not a batch job at month end. In Freightflow an invoice moves from draft to approved to registered, gets its IRN through a GSP and prints the IRN, acknowledgement and QR code on the PDF. The request and response for every attempt are kept, so a rejection can be read and fixed rather than guessed at.