GST e-invoicing explained: who needs it and how to comply

Under India’s GST e-invoicing system, certain B2B invoices must be registered on a government Invoice Registration Portal (IRP) before they are sent to the customer. The IRP validates the invoice and returns a unique Invoice Reference Number (IRN) and a signed QR code, which must appear on the invoice.

This guide explains who must comply, what changes in your billing process and how to automate it. It is a general overview, not legal advice — always check the latest CBIC notifications or speak with your chartered accountant.

Who needs to generate e-invoices?

E-invoicing applies to registered businesses whose aggregate annual turnover (AATO) has exceeded ₹5 crore in any financial year since 2017–18. The limit was reduced in stages from ₹500 crore when the system launched in October 2020, and has been ₹5 crore since 1 August 2023.

Once your turnover crosses the limit in any year, e-invoicing applies from then on, even if turnover later falls.

Which documents are covered?

• B2B tax invoices (supplies to other GST-registered businesses).
• Credit notes and debit notes issued to registered businesses.
• Export invoices and supplies to SEZ units.
• Supplies under reverse charge, where applicable.

Invoices to consumers (B2C) do not need an IRN, although very large businesses must print a dynamic payment QR code on B2C invoices.

Who is exempt?

Some categories are exempt regardless of turnover, including SEZ units (not SEZ developers), insurance companies, banks and NBFCs, goods transport agencies, passenger transport services, multiplex cinema admissions and government departments. Check the current notification for the full list.

How the e-invoicing process works

1. Create the invoice in your billing or accounting software as usual.
2. Upload it to the IRP in the standard JSON schema, directly or through your software’s integration.
3. Receive the IRN and signed QR code once the IRP validates the data.
4. Share the invoice with the IRN and QR code printed on it.
5. Auto-population: the details flow into your GSTR-1 and, for goods, can be used to generate the e-way bill.

An IRN can be cancelled within 24 hours on the IRP. After that, you must issue a credit note instead.

The 30-day reporting rule

Invoices must be reported to the IRP promptly. Businesses with AATO of ₹100 crore or more cannot report an invoice more than 30 days after its date, a rule in force since November 2023. GSTN extended the 30-day limit to businesses with AATO of ₹10 crore or more from 1 April 2025. If an invoice is reported late, the IRP rejects it, so build reporting into the billing process rather than doing it in batches at month end.

E-invoices and e-way bills

For movement of goods with a consignment value above ₹50,000, you generally need an e-way bill. When you generate an IRN, you can pass transport details at the same time and create the e-way bill from the same data, which avoids typing everything twice.

How to automate e-invoicing

Manual uploads work for a handful of invoices, but they break down as volume grows. Accounting software with built-in IRP integration, such as BlueSyntex Books, lets you:

• Generate the IRN and QR code with one click when you save an invoice.
• Validate GSTINs, HSN codes and tax amounts before submission to avoid rejections.
• Create e-way bills from the same invoice.
• Track which invoices are registered, cancelled or pending in one list.
• Reconcile the data with GSTR-1 before you file.

Quick compliance checklist

Want to see e-invoicing in action? Book a BlueSyntex Books demo and we will walk through your invoice flow.