E-invoicing is often described as "invoices go to the government". That is not quite it, and the difference matters.
What it actually is
You still raise your own invoice, in your own system, with your own numbering. What changes is that before you issue it, the invoice details are reported to the Invoice Registration Portal, which validates them and returns:
- an IRN — Invoice Reference Number, a unique hash for that invoice
- a signed QR code you print on the invoice
- a digitally signed copy of the invoice data
So it is registration, not generation. The invoice remains yours.
Who is covered
Applicability is based on aggregate annual turnover in a preceding financial year, and the threshold has been lowered repeatedly since e-invoicing began — each reduction pulling in a much larger group of smaller businesses.
Because the threshold has moved so often, check the figure currently in force rather than relying on what you remember. The important structural points do not change:
- It applies to B2B supplies, exports and supplies to government
- Once you are covered, you stay covered even if turnover later falls
- Some categories are specifically exempt regardless of turnover
Why it matters commercially
The IRN flows into the GST system, which means your invoice data reaches your buyer's GSTR-2B automatically and more reliably. That is genuinely good for everyone.
The flip side is enforcement by counterparty. If you are covered and you issue an invoice without an IRN, it is not a valid tax invoice — so your buyer's credit is at risk. Buyers with competent accounts teams check, and they will hold payment until you reissue.
What to do before you are covered
Know your number. Aggregate turnover is PAN-level across all GSTINs, not per registration. Businesses with more than one registration routinely underestimate it.
Check your billing software today. Not whether it "supports GST" — whether it can generate the e-invoice payload and register it. Adding this at the point you cross the threshold, mid-year, under pressure, is the expensive way.
Get master data clean first. E-invoicing validates strictly. Wrong GSTINs, bad HSN codes, missing pin codes fail at registration rather than being quietly accepted. Cleaning up customer and item masters in advance saves a difficult week.
Understand the cancellation window. An IRN can only be cancelled within a short window after generation, and not at all once it has been used. After that the correction route is a credit note. Sloppy invoicing gets expensive.
Practically
BizGST Pro exports the e-invoice IRN JSON on the Pro plan, with live IRN generation dependent on GSP integration and rolling out per plan. Whatever tool you use, the preparation is the same: know your turnover, clean your masters, and confirm your software can do it before you need it.
If you would rather someone else watched the threshold for you, our GST desk does exactly that.
General information, not tax advice. Thresholds and rules change frequently. Confirm current applicability with your chartered accountant.