Is e-invoicing mandatory for all businesses in India?

No. E-invoicing is mandatory only for businesses whose aggregate turnover has crossed Rs 5 crore in any year since 2017-18, and it applies to B2B invoices, exports, and credit/debit notes — not B2C sales. Smaller businesses below the threshold are not required to generate e-invoices yet.

What is an IRN in e-invoicing?

An IRN (Invoice Reference Number) is a unique code the government Invoice Registration Portal returns after validating your invoice. Along with a digitally signed QR code, it makes the invoice a legally valid tax invoice. Without a valid IRN, the invoice is not valid for ITC.

How long do I have to generate an e-invoice IRN?

Best practice is to generate the IRN at the moment of invoicing. Businesses with turnover of Rs 10 crore and above must report invoices to the IRP within 30 days of the invoice date, after which reporting is blocked and the buyer cannot claim ITC.

E-Invoicing in India 2026: Complete Requirements and IRN Generation Process

What E-Invoicing Actually Is

E-invoicing does not mean emailing a PDF. It means every B2B invoice is reported to a government Invoice Registration Portal (IRP), which validates it and returns a unique Invoice Reference Number (IRN) and a signed QR code. Only then is the invoice legally valid for the transaction. It is a reporting layer on top of your normal invoice, designed to curb fake invoicing and pre-fill your returns.

Who Must Comply in 2026

E-invoicing is mandatory for businesses whose aggregate turnover has crossed Rs 5 crore in any financial year since 2017-18. The threshold has stepped down steadily, so if you are near it, plan ahead. Key points:

Applies to B2B invoices, exports, and credit/debit notes — not B2C.
Once you cross the threshold, it applies from the following financial year and does not reverse if turnover later dips.
Businesses at Rs 10 crore and above also face a 30-day IRN reporting limit from the invoice date.

Not sure if you qualify? Our e-invoice limit guide walks through the edge cases.

What an E-Invoice Must Contain

Supplier and recipient GSTIN and details.
Invoice number, date, and type.
Item lines with HSN/SAC codes, quantities, rates, and the correct GST slab.
Taxable value, tax breakup (CGST/SGST or IGST), and total.
After IRP registration: the IRN, a digitally signed QR code, and an acknowledgement number.

The IRN Generation Process

Your billing system builds the invoice in the government JSON schema, sends it to the IRP (directly or via a GST Suvidha Provider), and the IRP validates it, de-duplicates it, signs it, and returns the IRN and QR code. This should happen at the moment of invoicing — not as a monthly batch — so nothing slips past the reporting window.

The QR Code and E-Way Bill Link

The signed QR code encodes the key invoice details and lets anyone verify the invoice is genuine. E-invoicing also connects to the e-way bill system, so transport documentation can be generated from the same data, reducing duplicate entry for goods movement.

What Happens If You Do Not Comply

An invoice without a valid IRN is not a valid tax invoice — your customer cannot claim ITC.
Penalties apply for non-generation or incorrect e-invoices.
Goods can be detained in transit if the e-invoice or e-way bill is missing.

How to Get Ready

Confirm your turnover against the Rs 5 crore threshold.
Make sure your billing software supports IRP integration and IRN generation.
Clean up your item master — HSN codes and rates must be correct for the JSON to validate.
Build IRN generation into the point of invoicing, not a monthly catch-up.

Conclusion

E-invoicing is now a core part of GST compliance for mid-sized and growing businesses. The requirements are strict, but with software that talks to the IRP for you, generating an IRN and QR code becomes an invisible step in normal billing. InfiBis handles e-invoice generation as part of the invoicing flow, and you can read the fundamentals of a compliant invoice in our GST invoice guide.