India e-Invoicing, explained

The name misleads almost everyone the first time. Indian e-invoicing is not about producing invoices electronically instead of on paper. It is a registration step: the invoice is submitted to a government portal in advance and comes back with a unique identifier.

The mechanics: you create the invoice in your own ERP or accounting system, convert it to the government's standard format (FORM GST INV-01, expressed as JSON), and upload it to an Invoice Registration Portal. The IRP validates it and returns an IRN — a 64-character hash — along with an acknowledgement number, an acknowledgement date and a digitally signed QR code.

In most countries an electronic tax invoice is simply transmitted to the tax authority and the document itself stays as the issuer made it. India is different. Without the IRN and QR that the IRP returned, the document 'shall not be treated as an invoice' (CGST Rule 48(5)). It is not a defective invoice — in law it is not an invoice at all.

In practice that means your Indian customer cannot claim input tax credit on it. They have paid you, their credit is blocked, and they will ask for a reissue immediately. If a financial year closes in the meantime, correcting it becomes considerably harder.

There is an upside. Once an IRN exists, the data flows automatically into the relevant tables of GSTR-1 and into Part-A of the e-way bill. Three separate keyings collapse into one.

The rule is CGST Rule 48(4), and the current threshold comes from Notification 10/2023-Central Tax: aggregate annual turnover above ₹5 crore. It took effect on 2023-08-01 and is unchanged as of August 2026.

The part people get wrong is which year you measure. It is not the previous year alone. If turnover exceeded ₹5 crore in any financial year from 2017-18 onwards, you are covered from the following financial year, and you stay covered even if turnover later falls. Once in, always in.

Aggregate annual turnover is computed on a PAN basis across the whole of India. Several GSTINs across several states still count as one figure. It adds taxable supplies, exempt supplies, exports and inter-state supplies to your own units, and excludes GST itself. It is not the parent company's revenue and not a converted figure in another currency.

The covered documents are B2B supplies (to a registered recipient), supplies to SEZ units, exports, deemed exports, and credit and debit notes against them. B2C invoices are outside e-invoicing. Exports to your own parent company abroad are inside it — that one is missed often.

Some suppliers are exempt by notification: SEZ units (developers are not), insurers, banks and financial institutions including NBFCs, goods transport agencies, passenger transport, admission to cinemas, and government departments and local authorities. Mixed businesses need a professional view.

You will see reports that the threshold is dropping to ₹1 crore. As of August 2026 no such notification has been issued. Until it appears in the gazette, the threshold is ₹5 crore.

There are two reasons: we cannot, and we must not.

Only an IRP issues an IRN. There are six of them — two operated by NIC and four by private operators — and none of them delegates issuance to arbitrary third-party software.

Direct API access is restricted. It is opened to taxpayers above the threshold acting for their own GSTIN, and to businesses already registered on the e-way bill system. Any other software must go through a GST Suvidha Provider, which involves a commercial contract, security undertakings and infrastructure commitments. Adullam Tools is a free tool with no GSP contract.

The second reason matters more. If we drew something that looked like an IRN, or painted a QR code that resembled the real one, that would be a forged document. The genuine QR carries the IRP's digital signature and can be checked with the official verification app. Producing a lookalike would feel helpful for about a day and then leave the user holding the consequences in an audit. So we do not.

What we can do is well defined: build accurate JSON against the government schema and tell you in advance what the IRP is likely to reject. That is exactly where the time goes in practice.

Prepare first. On the e-invoice master portal, check whether your GSTIN is enabled for e-invoicing. If you are over the threshold but not listed, you can request self-enablement on the portal. Until it is enabled, uploads are blocked.

Step one — draft the invoice in the Adullam Tools GST invoice tool. The Rule 46 particulars and the place of supply are resolved before you download the INV-01 JSON. Read the pre-upload checks before you download.

Step two — sign in to the NIC e-invoice portal. For volume, use e-Invoice → Bulk Upload and submit the JSON file directly. For one or two documents, the GePP tool (a free Excel-based utility) is quicker. Both are linked above under government portals and offline tools.

Step three — the IRP returns the IRN, acknowledgement number, acknowledgement date and signed QR. Record them in your accounting system and put the QR and IRN on the document you give the customer. Only then is it a tax invoice.

If it is rejected, the portal returns an error code and message. Look it up in the rejection table above. Most failures are one of three things: tax totals, tax heads, or HSN digits.

India has two deadlines here with different purposes, and treating them as one causes real damage.

First, the deadline to issue the invoice (CGST Rule 47). Goods: at the time of removal. Services: within 30 days of supply. Banks, financial institutions and NBFCs: 45 days. This governs when the document must exist.

Second, the deadline to report it to the IRP. Suppliers with aggregate turnover of ₹10 crore and above must report within 30 days of the document date. It took effect on 2025-04-01; before that the threshold was ₹100 crore (GSTN advisory dated 2024-11-05). It applies to invoices, credit notes and debit notes alike.

After 30 days the IRP refuses the document. This is a system block, not a matter of discretion. No IRN means no valid tax invoice, and there is effectively no way back. An invoice dated 1 April 2026 must be reported by 30 April 2026.

Below ₹10 crore there is currently no such window. Even so, the IRN has to exist before the GSTR-1 filing for the period, so batching everything into the last days of the month is risky.

Cancellation is possible only on the IRP and only within 24 hours. After that the IRP cannot touch it and the adjustment has to run through a credit note or debit note.

There is no concept of amendment on the IRP. If you got it wrong, cancel within 24 hours and re-report under a new number, or adjust with a note. Do not reuse the cancelled document number — that returns a duplicate IRN error.

If the movement needs an e-way bill, Part-A is populated when the IRN is generated. Part-B (vehicle details) is still entered separately.

The document you hand over should carry the IRN, acknowledgement number, acknowledgement date and the signed QR. The QR is scanned for verification, so print it at a quality that survives scanning.

Retention follows the usual GST rules. The IRP keeps uploaded data for only 24 hours, so if you do not store the IRN response in your own system, you cannot retrieve it later.

Assuming a home-country e-invoicing system covers this. It does not. A document issued under an Indian GSTIN follows Indian rules.

Measuring turnover wrongly. It is the PAN-level all-India figure, not the parent company's revenue and not one state's GSTIN in isolation.

Leaving exports out. Supplies to your own parent company abroad are covered. Only B2C is outside.

Handing over a PDF with no IRN. The Indian customer loses input tax credit, complains, and the reissue disturbs your number sequence as well.

Confusing the two 30-day rules. The Rule 47 issue deadline for services and the IRP reporting window are separate obligations, and both apply.

Carrying over the head-office numbering scheme. India caps the number at 16 characters with a restricted character set: INV-2026-27-00001 is 17 characters and will be rejected.