E-Invoicing Rules in India: Threshold, IRN and Who's Exempt

E-invoicing means that once your turnover crosses a government-notified threshold, your B2B invoices aren't valid for GST purposes just because you generated them — they need to be reported to a government portal first, which validates the invoice and issues a unique reference number. Below the threshold, and for several exempt categories, none of this applies and a normal invoice is all you need.

What actually happens during e-invoicing?

A notified taxpayer generates their invoice as usual (through whatever billing tool or software they use), then reports its details to the government's Invoice Registration Portal (IRP). The IRP validates the invoice, assigns it a unique Invoice Reference Number (IRN), and returns a signed QR code. This IRN and QR code are then meant to be added to the invoice before it's issued to the customer. Until this step happens, the invoice — even if it looks complete and correctly formatted — isn't treated as a valid tax invoice for notified taxpayers.

Who has to comply — what's the turnover threshold?

The threshold is based on Aggregate Annual Turnover (AATO) in any preceding financial year, and it has been lowered several times by government notification since e-invoicing was first introduced for large taxpayers — most recently extending down to businesses with AATO above ₹5 crore. Because this number has moved before and can move again, treat it as a starting point for a rough check, not a fixed rule — the safest way to confirm whether you're currently covered is to check your GSTIN's status directly on the e-invoice portal or the GST portal.

What's the 30-day reporting rule?

For larger taxpayers above a higher specified AATO band, there's an additional constraint: the IRN must be generated within 30 days of the invoice date. After that window closes, the portal will reject the reporting attempt for that invoice entirely. In practice, this means e-invoicing isn't something you can batch up and deal with weeks later — invoices need to be reported close to when they're issued, or you risk being unable to report them at all.

Who's exempt regardless of turnover?

A specific set of categories is generally kept outside the e-invoicing mandate no matter how large they are:

• Special Economic Zone (SEZ) units — note this doesn't extend to SEZ developers, who are not exempt
• Insurers
• Banking companies and other financial institutions, including NBFCs
• Goods Transport Agencies (GTAs) transporting goods by road
• Passenger transport service providers
• Suppliers of services by way of admission to exhibition of cinematograph films in multiplexes
• Government departments and local authorities

If your business doesn't fall into one of these categories, the AATO threshold is what determines whether you're covered — the exemptions above apply independently of turnover.

Does this apply to B2C sales?

No — B2C invoices are outside the B2B e-invoicing/IRN framework described above. A separate rule requiring a dynamic QR code on B2C invoices can apply to large suppliers instead (turnover above ₹500 crore) — a distinct requirement with its own threshold, generated by the supplier rather than the IRP. See our dynamic QR code guide for what it covers and who it applies to.

Threshold and exemption summary

Why this connects back to invoice numbering

IRN generation depends on submitting a complete, correctly-formed invoice — including a valid, properly-sequenced invoice number — to the portal. If your numbering has gaps, duplicates, or doesn't follow the consecutive-serial-number requirement, that's a problem worth fixing before it becomes an e-invoicing problem too. See our GST invoice numbering rules guide for what "consecutive" actually requires, and our step-by-step invoice creation guide for how auto-incrementing numbering avoids these mistakes in the first place.