Billing & Invoicing Software · Updated 20 Oct 2026

E-Invoicing in India Explained for Small and Growing Businesses

What e-invoicing is, who must generate e-invoices under GST, what IRN and QR codes mean, and how billing software handles it.

Key takeaways
  • E-invoicing means reporting B2B invoices to the Invoice Registration Portal (IRP), which returns an IRN and signed QR code.
  • It applies to businesses above the notified aggregate turnover threshold — currently ₹5 crore.
  • Good billing software generates e-invoices with one click.

"E-invoice" does not mean any invoice sent by email. Under GST it has a specific meaning: a B2B invoice that has been reported to the government's Invoice Registration Portal and authenticated.

How it works

  1. You create an invoice in your billing or accounting software.
  2. The software sends the invoice details to the IRP in a standard format.
  3. The IRP validates it and returns a unique Invoice Reference Number (IRN) and a digitally signed QR code.
  4. You print or send the invoice with the IRN and QR code. Details also flow into GST returns.

Who needs it

E-invoicing is mandatory for GST-registered businesses whose aggregate annual turnover in any financial year since 2017-18 exceeds the notified threshold — currently ₹5 crore — for B2B supplies, exports and certain other documents. Some sectors are exempt. Larger businesses also face time limits for reporting invoices to the IRP. Thresholds and rules are changed by notification, so confirm current requirements on the official GST and e-invoice portals or with your CA.

What to look for in software

  • Direct IRP integration so you do not upload JSON files manually.
  • Automatic e-way bill generation with the e-invoice where needed.
  • Bulk e-invoicing for high volumes.
  • Clear error messages when the IRP rejects an invoice.

See billing software that supports GST and read our GST invoice format guide.

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