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- E-invoicing is mandatory if your turnover crossed ₹5 crore in any financial year from 2017-18 onwards.
- You still make the invoice in your own software. The IRP validates it and returns an IRN and a signed QR code.
- It covers B2B invoices, exports, and credit and debit notes, not sales to consumers.
- An invoice without an IRN is not a valid tax invoice when e-invoicing applies to you.
E-invoicing does not mean sending invoices by email, and it does not mean creating invoices on a government website. You make the invoice in your own billing software as always. The difference is that each B2B invoice is reported to a government-approved portal, which stamps it with a unique number before it goes to your buyer.
Who Needs to Do It
E-invoicing is mandatory if your aggregate annual turnover was more than ₹5 crore in any financial year from 2017-18 onwards. Once you cross the limit in any one year, you stay covered even if turnover later falls.
The limit came down in steps, which is why many mid-sized businesses joined only recently.
- Oct 2020Above ₹500 crore
- Jan 2021Above ₹100 crore
- Apr 2021Above ₹50 crore
- Apr 2022Above ₹20 crore
- Oct 2022Above ₹10 crore
- Aug 2023Above ₹5 croreThe limit that applies today.
It applies to B2B tax invoices, export invoices, and credit and debit notes. It does not apply to sales to unregistered consumers. Certain businesses are exempt whatever their turnover, including banks and financial institutions, insurers, goods transport agencies, passenger transport services and SEZ units.
How an Invoice Gets Its IRN
- You raise the invoiceIn your billing software
- Sent to the IRPIn the standard format
- IRP validates itAnd checks for duplicates
- IRN and QR returnedDigitally signed
- Invoice to the buyerWith the QR code printed
The IRN (Invoice Reference Number) is a unique 64-character code for that invoice. The QR code carries the key details and the portal’s digital signature, so anyone can verify that the invoice is genuine.
Two useful things happen automatically after that. The invoice details flow into your GSTR-1, and they can be used to generate the e-way bill without typing them again.
Rules to Remember
- Report on time. Businesses with turnover of ₹10 crore or more must report an invoice to the IRP within 30 days of the invoice date. The portal rejects older documents. Even if you are below that, report at the time of billing.
- Cancel within 24 hours. After that, use a credit or debit note.
- No edits. A reported e-invoice cannot be changed on the IRP.
- Print the QR code. The copy you give the buyer must carry it.
Check Whether You Have Crossed the Limit
Look at your turnover for every financial year since 2017-18, across all GSTINs under the same PAN, and include exempt and export sales. Many businesses cross ₹5 crore in one good year and do not notice. You can also check your status on the e-invoice portal using your GSTIN.
Keep It Inside Your Billing
Uploading invoices to a portal one by one is slow and easy to forget. With Saniiro E-Invoicing, the IRN and signed QR code are generated from the invoice screen and saved on the invoice, so billing staff do not change how they work. Next, see the 16 fields every GST invoice needs.
This article is general information as of 6 October 2026, not tax or legal advice. GST rules, limits and due dates change by notification, so check the GST portal or ask your chartered accountant before you act on it.