e-Invoicing in India: who needs it and how it works
"e-Invoice" does not mean a PDF sent by email. It means your invoice is registered with the government at the moment you issue it — reported to an Invoice Registration Portal, stamped with a unique number and a QR code, and only then legally valid. Here is who must do it, and what actually changes in your billing day.
Who must e-invoice
e-Invoicing is mandatory for businesses whose aggregate annual turnover has crossed ₹5 crore in any financial year since 2017-18 (the threshold has ratcheted down over the years — ₹500 crore in 2020 to ₹5 crore now). It applies to B2B invoices, exports, credit and debit notes — not to B2C sales. Once the threshold catches you, it applies from the next financial year onward, permanently.
A few sectors are exempt regardless of size (banks, insurers, transport of passengers, cinema, and some others) — if you are not one of those, assume the turnover test decides.
The vocabulary, in one table
| Term | What it is |
|---|---|
| IRP | Invoice Registration Portal — the government system that receives and registers your invoice. |
| IRN | Invoice Reference Number — a unique 64-character hash the IRP assigns. An invoice that should carry an IRN and doesn't is not a valid invoice. |
| Signed QR code | The IRP's digitally-signed stamp, printed on the invoice — anyone can scan it to verify the invoice is registered. |
| GSP / API access | A paid pipe that lets software submit invoices to the IRP automatically instead of you uploading them. |
How an e-invoice actually flows
- You create the invoice in your billing software, exactly as before.
- The software builds the invoice in the government's INV-01 JSON schema and sends it to the IRP (directly via API, or you upload the JSON on the portal).
- The IRP validates it, generates the IRN, signs the QR code, and returns both in seconds.
- You print/send the invoice with the IRN and QR on it. Only now is it a legal invoice.
- The registered invoice auto-populates your GSTR-1, and its details pre-fill Part A of the e-way bill if goods are moving — one entry, three compliances.
- Made a mistake? An e-invoice can be cancelled within 24 hours on the IRP; after that, corrections go through credit/debit notes.
Larger businesses also face a reporting window — invoices must reach the IRP within 30 days of the invoice date (currently enforced for higher-turnover slabs). The safe habit at any size: register at the moment of invoicing, not in a weekly batch.
Do you need a GSP subscription?
Only for the fully-automatic path. Without one, your software can still produce the exact INV-01 JSON and you upload it on the government's portal yourself — a few extra clicks, zero extra subscription cost. Most businesses start this way and buy API access when invoice volume makes the clicks expensive.
Common early mistakes
- Sending goods with an invoice whose IRN "will be generated later" — the invoice is not valid in transit, and detention is expensive.
- Treating the 24-hour cancellation window as an editing tool — plan invoice review before registration, not after.
- Registering B2C invoices — not required, and it clutters your GSTR-1 auto-population.
- Letting a second billing tool (a POS, a spreadsheet) issue invoices outside the e-invoice flow — every invoice must go through the same door once you are in the regime.
Arthora ERP produces the IRP payload, prints the QR, drives the e-way bill and builds GSTR-1 — from one entry. 7-day free trial, no card.