E-invoicing under GST, explained step by step
E-invoicing does not mean generating an invoice electronically — almost everyone already did that. It means reporting the invoice to a government portal and receiving back a number that makes it valid. That distinction is the whole subject.
- IRN
- A 64-character hash uniquely identifying the invoice
- Acknowledgement
- A number and timestamp for the reporting
- Signed QR
- A digitally signed code carrying the key fields
- Signed invoice
- The JSON, signed by the portal
The parts of the system
Who it applies to
B2B supplies by businesses above the turnover threshold notified by the GST Council. The threshold has been lowered several times since 2020, so check the current notification rather than assuming.
What an IRN is
The Invoice Reference Number — a 64-character hash computed from your GSTIN, the document type, the number and the financial year. It is unique, and it is what makes the invoice reportable exactly once.
The signed QR code
A digitally signed code containing the key invoice fields, which must be printed on the invoice so it can be verified without access to any system.
What is not e-invoiced
B2C supplies, exempt supplies and certain notified sectors. A B2C invoice may still need a dynamic QR code, which is a different requirement.
Reporting, not filing
Reporting an invoice to the IRP is not filing a return. The reported invoice flows into GSTR-1, but the return is still filed separately.
Time limits
Large taxpayers have faced a limit on how old an invoice can be when reported. Reporting late can mean not being able to report at all.
How the process runs
- Raise the invoice. In your own system, with all the mandatory particulars and the fields the e-invoice schema requires.
- Build and validate the payload. The schema is strict about unit codes, GSTIN formats and rate combinations. Validating before sending is what turns twelve rejections a month into none.
- Report to the IRP. The portal returns the IRN, an acknowledgement number and date, and the signed QR code.
- Print and file. The IRN and QR go on the invoice the customer receives, and the reported invoice flows into the GSTR-1 working.
E-invoicing questions
Does e-invoicing mean the government generates my invoice?
No. You generate the invoice in your own system exactly as before; e-invoicing means reporting it to the Invoice Registration Portal and receiving an IRN and signed QR back, which then have to appear on the document you give the customer.
What happens if the IRP is down?
The invoice is still a valid document; it simply has not been reported yet. Practically you queue it and retry, and the thing that matters is having a register of what is unreported so nothing is discovered at filing time.
Can an e-invoice be cancelled?
Within the cancellation window the IRP allows, which is short. After that the correct instrument is a credit note against the original invoice, linked to its IRN.
Is this page tax advice?
No — it is a plain-language explanation, and the thresholds and time limits have changed repeatedly. Confirm the current position with your tax adviser or the notification before relying on it.
Related
Find out which invoices would be rejected
tBiz validates the e-invoice payload while you are still on the invoice, and keeps a register of what is unreported.