E-invoicing is no longer just a big-company problem. As the turnover threshold has stepped down, mid-size manufacturers, exporters and B2B service firms have been pulled in — and a missed IRN can cost your buyer their input credit, which quickly becomes a commercial problem for you. Here is who is covered in 2026, the time limits, and how to comply cleanly.
What e-invoicing actually is
E-invoicing does not mean generating invoices on a government portal. You still raise the invoice in your own system. The difference is that each B2B invoice is reported to the Invoice Registration Portal (IRP), which returns:
- An IRN (Invoice Reference Number) — a unique fingerprint of the invoice.
- A signed QR code that must be printed on the invoice.
The data then auto-populates your GSTR-1 and your buyer’s GSTR-2B. In effect, the invoice becomes “official” only once it carries a valid IRN.
Who must comply in 2026
- Applicability is driven by aggregate annual turnover crossing a notified threshold in any year since GST began.
- The threshold has been progressively lowered, so many businesses that were once exempt are now covered.
- It applies to B2B supplies, exports and supplies to SEZ — generally not B2C.
- A few categories (e.g. certain financial, transport and SEZ units) are specifically excluded.
The most common surprise: a business crosses the threshold in one year and stays covered even if turnover later dips. Check your applicability against every past year, not just the current one.
Every time this threshold drops, I get the same call a month too late: “we crossed the limit last year, nobody told us, and now our buyer is holding payment because the invoice has no IRN.” E-invoicing is not really a tax rule — it is a cash-flow rule, because your customer’s input credit now hangs on your IRN. If your turnover is anywhere near five crore, switch it on before you are forced to, not after a buyer refuses to pay.
— Hardik Garg, Founder & Senior Advisor
Not sure if e-invoicing applies to you?
We confirm applicability, set up IRN generation in your billing flow, and make sure your GSTR-1 and your buyers’ 2B line up.
The reporting time limit that trips people
For covered businesses, invoices must be reported to the IRP within a limited window of the invoice date — not whenever convenient. Report late and the IRP can reject the invoice, leaving you with a document that is invalid for GST. Larger taxpayers in particular have shorter windows, so e-invoicing has to be part of the billing moment, not a month-end task.
Why a missing IRN hurts your buyer
If a covered supplier issues a B2B invoice without a valid IRN:
- The invoice is not legally valid for GST purposes.
- It will not flow correctly into the buyer’s GSTR-2B.
- The buyer’s input tax credit is at risk — and they will come back to you.
This is why large buyers now refuse invoices without QR codes. E-invoicing compliance is, increasingly, a condition of doing business.
How to comply without disrupting billing
- Integrate IRN generation into your ERP/billing software so it happens at invoice creation.
- Print the QR code and IRN on every B2B invoice.
- Reconcile e-invoiced data against GSTR-1 monthly to catch failures.
- Train billing staff on the time limit and on cancellation/amendment rules.
Want e-invoicing handled end-to-end?
From applicability to ERP integration to monthly reconciliation — our compliance desk keeps it running so billing never stalls.
The bottom line
The direction of travel is one-way: the e-invoicing net keeps widening and the floor keeps falling. If you are above the current limit this is not optional, and a missing IRN can quietly freeze your buyer’s credit. If you are below it but growing, treat e-invoicing as a switch you flip early — being ready costs almost nothing next to a held payment. Check your aggregate turnover against the current threshold today, and wire e-invoicing into your billing before the next notification names you.