E-Invoicing Under GST: Who Must Generate an IRN and When

E-invoicing is mandatory for any GST-registered business whose aggregate turnover crossed ₹5 crore in any financial year from 2017-18 onwards. You must report each B2B invoice, export invoice, and credit or debit note to the Invoice Registration Portal (IRP), which returns an Invoice Reference Number (IRN) and a signed QR code. If your turnover is ₹10 crore or more, you must do this within 30 days of the invoice date.

E-invoicing doesn’t mean the government makes your invoice. You still raise it in your own software. You then upload its details to the IRP, which validates them, gives the invoice a unique IRN and passes the data to your GSTR-1 and the e-way bill system.

Who needs to generate e-invoices?

The test is your aggregate turnover (total turnover of all GSTINs under the same PAN, across India) in any preceding financial year from 2017-18 onwards.

Phase	Turnover threshold	Applicable from
Earlier phases	₹500 cr → ₹100 cr → ₹50 cr → ₹20 cr → ₹10 cr	Oct 2020 to Oct 2022
Current	More than ₹5 crore	1 August 2023 (Notification 10/2023-Central Tax)

Example: Your turnover was ₹5.4 crore in FY 2022-23 but fell to ₹4.1 crore in FY 2024-25. E-invoicing still applies, because you crossed ₹5 crore in a preceding year.

Watch out: Turnover is calculated at PAN level. If two GSTINs under the same PAN together cross ₹5 crore, both must e-invoice, even if each alone is below the limit.

Which businesses are exempt from e-invoicing?

These classes of taxpayers don’t need to generate IRNs, even above the threshold:

• Special Economic Zone (SEZ) units (SEZ developers are not exempt)
• Insurance companies
• Banking companies, financial institutions and NBFCs
• Goods Transport Agencies (GTAs)
• Suppliers of passenger transportation services
• Suppliers of admission to cinema screenings in multiplexes
• Government departments and local authorities

If you are exempt but your turnover is above the threshold, your invoices must carry the declaration under Rule 46(s): “I/We hereby declare that though our aggregate turnover in any preceding financial year from 2017-18 onwards is more than the aggregate turnover notified under sub-rule (4) of rule 48, we are not required to prepare an invoice in terms of the provisions of the said sub-rule.”

Which documents need an IRN?

Covered	Not covered
Tax invoices for B2B supplies	B2C invoices (sales to consumers or unregistered persons)
Exports (with or without IGST)	Bills of supply
Supplies to SEZ units/developers	Delivery challans
Deemed exports	Import bills of entry
Credit notes and debit notes on the above	Self-invoices under reverse charge

Large-business B2C rule: businesses with aggregate turnover above ₹500 crore don’t generate IRNs for B2C invoices, but must print a dynamic QR code on them.

What is the 30-day time limit for reporting e-invoices?

From 1 April 2025, if your aggregate turnover (AATO) is ₹10 crore or more, the IRP rejects any invoice, credit note or debit note dated more than 30 days before the date you try to report it. GSTN first applied this limit to businesses with AATO of ₹100 crore and above, then lowered the threshold to ₹10 crore.

Example: An invoice dated 1 April 2026 must be reported by 30 April 2026 (GSTN’s own example in its advisory). After that, the IRP won’t generate an IRN for it. In practice you would have to raise a fresh, correctly dated invoice.

If your AATO is between ₹5 crore and ₹10 crore, this hard 30-day stop doesn’t apply as of now. You should still generate the IRN before you send the invoice to the buyer, because an invoice without an IRN is not valid.

How to generate an IRN: step by step

1. Register on an IRP (for example einvoice1.gst.gov.in) using your GSTIN. Multi-factor authentication is mandatory on the e-invoice and e-way bill portals for all taxpayers since 1 April 2025.
2. Create the invoice in your billing or accounting software in the standard e-invoice schema (INV-01).
3. Upload the JSON to the IRP, directly through the portal, through your software’s API, or through a GST Suvidha Provider.
4. The IRP validates the data and returns the IRN, acknowledgement number and a signed QR code.
5. Print the QR code on the invoice and send it to the buyer.
6. The data flows automatically into your GSTR-1 and, if you give transport details, into an e-way bill.

Tip: Fill in the vehicle or transporter details when you generate the IRN and Part A of the e-way bill is created for you. See our e-way bill guide.

What happens if you don’t generate an e-invoice?

• Invoice not valid: Under Rule 48(5), an invoice that should have been e-invoiced but wasn’t is not treated as a tax invoice.
• Buyer loses ITC: The invoice won’t flow correctly into the buyer’s GSTR-2B, so they can’t claim input tax credit. Your buyer will likely chase you or hold back payment. (More in our guide on ITC not showing in GSTR-2B.)
• Penalty: Under Section 122, issuing an incorrect invoice or none at all attracts a penalty of ₹10,000 or the tax involved, whichever is higher. Section 125’s general penalty of up to ₹25,000 can also apply.
• E-way bill problems: Goods moving on a non-compliant invoice can be detained.

Common mistakes with e-invoicing

1. Checking only the current year’s turnover. The rule looks back to 2017-18.
2. Forgetting credit and debit notes. They need IRNs too.
3. Reporting late if your turnover is ₹10 crore or more. Once the 30-day window closes, the IRP won’t accept the invoice.
4. Trying to cancel after 24 hours. An IRN can be cancelled only within 24 hours, and only in full. After that, issue a credit note.
5. Editing the invoice after the IRN is generated. The printed invoice must match what was reported, or the buyer’s ITC and your GSTR-1 won’t reconcile.
6. Missing the Rule 46(s) declaration on invoices if you are an exempt category above the threshold.

What to do next

• Check your aggregate turnover for every year since FY 2017-18, at PAN level.
• If you cross ₹5 crore, make sure your billing software supports IRP integration before you raise the next B2B invoice.
• Make sure your invoice format is otherwise correct, because the IRP validates GSTINs, HSN codes and tax calculations.

Not sure whether e-invoicing applies to you, or need help with a rejected IRN? Request a callback and our team will review your turnover history.