e-Invoicing under GST: who must generate an IRN, and what your billing software has to do

e-Invoicing under GST means reporting a business-to-business invoice to a government Invoice Registration Portal before you give it to the customer, and printing the Invoice Reference Number and signed QR code the portal returns. It is mandatory for a registered person whose PAN-level aggregate annual turnover crossed ₹5 crore in any financial year from 2017-18 onwards, unless the business falls in an exempt category. That threshold has applied since 1 August 2023 and still stands as this is written; the e-invoice portal is the place to confirm it before you act.

How the threshold has moved

Two details catch people out. The test is any financial year since 2017-18, not the current one: a business that touched ₹5 crore once in 2021-22 and has fallen below it since is still covered. And turnover is aggregated across every GSTIN under the same PAN, so three small branch registrations in three states are added together.

What is covered, and what is not

• Covered: B2B supplies to registered persons, supplies to SEZ units, exports, deemed exports, and the credit and debit notes raised against them.
• Not covered: B2C invoices. A separate rule requires a dynamic QR code on B2C invoices for very large taxpayers only.
• Exempt by category, whatever the turnover: banks, insurers and non-banking financial companies, goods transport agencies, passenger transport services, admission to cinema exhibitions, SEZ units, and government departments and local authorities.
• A bill of supply under composition is not an e-invoice, because composition dealers are outside the scheme.

What actually happens when an invoice is reported

1. Your software builds the invoice as a JSON document in the government schema, with your GSTIN, the buyer's GSTIN, item lines with HSN, rates, taxable values and place of supply.
2. It sends that JSON to an Invoice Registration Portal, directly or through a GST Suvidha Provider.
3. The portal validates it, generates a 64-character Invoice Reference Number, signs the document and returns it with a QR code and an acknowledgement number.
4. Your software stores all three against the invoice and prints the QR code on the copy the customer gets. An invoice in a covered category without an IRN is not a valid tax invoice.
5. The reported data flows on: it auto-populates your GSTR-1 and can supply Part A of an e-way bill, so the same figures are not typed three times.

Cancellation is where billing habits have to change. An IRN can be cancelled on the portal within 24 hours of generation, and not after. Beyond that window the only correction is a credit note. A shop used to editing yesterday's bill has to stop editing yesterday's bill.

Larger taxpayers also face a reporting time limit: invoices must reach the portal within 30 days of the invoice date. The turnover level at which that limit applies has been lowered in stages, so check the current advisory rather than assuming you are below it.

Six things software must do before it is e-invoice ready

1. Produce schema-valid JSON, including the fields nobody thinks about: place of supply, reverse charge flag, unit codes in the government list, and correct rounding.
2. Connect to an IRP, handle the portal being slow or down, and retry without creating a duplicate.
3. Store the IRN, acknowledgement number, acknowledgement date and signed QR against the invoice, permanently.
4. Print the QR code at a size a scanner can actually read on the bill design the customer receives.
5. Support cancellation inside 24 hours, and force a credit note after it.
6. Reconcile: show you which reported invoices did not reach GSTR-1, and which GSTR-1 rows have no IRN.

Ask a vendor to demonstrate points three, five and six. Point one is table stakes and every vendor will claim it.

Where Tatva ERP stands on this

Tatva ERP produces GST invoices, registers, the HSN summary and GSTR-1, GSTR-2 and GSTR-3B summaries with the GSTR-1 portal JSON. It does not generate IRNs and it does not generate e-way bills today. If your turnover is above the e-invoice threshold, that matters, and we would rather say so here than after you have paid. Businesses below the threshold, which is most single-branch retailers, distributors and service firms, are unaffected.

We publish this the same way we publish prices: the question a buyer will ask in month three should be answered in month zero. The same principle is in why we publish prices ex GST.

Frequently asked questions

What is the e-invoice turnover limit in India?

₹5 crore of PAN-level aggregate annual turnover in any financial year from 2017-18 onwards, applicable since 1 August 2023. Once you cross it in any year, e-invoicing applies to your covered supplies from then on, even if turnover later falls. Confirm on the e-invoice portal, which also has a search to tell you whether a given GSTIN is enabled.

Do I need an IRN for retail counter sales?

No. e-Invoicing covers B2B supplies, exports, SEZ supplies and deemed exports. A sale to a walk-in customer without a GSTIN is B2C and needs no IRN. A shop that also sells to registered dealers needs IRNs for those invoices only, which is why the software has to decide per invoice, not per day.

Can an e-invoice be edited or cancelled?

It cannot be edited. It can be cancelled in full on the portal within 24 hours of the IRN being generated, and cancelled invoice numbers cannot be reused in the same financial year. After 24 hours, the correction is a credit note or a debit note, which is itself reported.

Does e-invoicing replace the e-way bill?

No. They are separate systems that share data. Reporting an invoice can populate Part A of the e-way bill, but the vehicle details in Part B and the movement rules are still the e-way bill's own, on the e-way bill portal.