E-Invoicing at ₹5 Crore: What Small Businesses Must Do and the Mistakes to Avoid

GST e-invoicing is mandatory for every registered business whose aggregate turnover exceeded ₹5 crore in any financial year since 2017-18: each B2B invoice, export invoice and related credit or debit note must be registered on an Invoice Registration Portal (IRP), which returns an Invoice Reference Number (IRN) and QR code to print on it. Businesses with turnover of ₹10 crore or more must also report each invoice within 30 days of its date. An invoice without a required IRN is not a valid tax invoice, so the buyer's input tax credit is at risk.

Sources checked: 20 October 2026

Facts checked on 20 October 2026 against Notification 10/2023-Central Tax, GST portal advisories 396, 543 and 678 and the GST Council's press release of 8 October 2026.

Key facts

Item	E-invoicing, October 2026
Threshold	Aggregate turnover above ₹5 crore in any financial year from 2017-18 (from 1 August 2023)
Documents	B2B tax invoices, exports, supplies to SEZs, related credit and debit notes
Not covered	B2C invoices, bills of supply, delivery challans
Exempt taxpayers	SEZ units, insurers, banks and financial institutions including NBFCs, goods transport agencies, passenger transport, multiplex admissions, government departments and local authorities
30-day reporting limit	Turnover ₹10 crore and above (from 1 April 2025); none below ₹10 crore as of now
Cancelling an IRN	Within 24 hours, and not if an active e-way bill exists
Penalty	₹10,000 or tax evaded, whichever is higher (s.122(1)(i)); general penalty up to ₹25,000 (s.125)
Pending change	RCM self-invoices and import of services (above ₹5 crore) — recommended 8 Oct 2026, start date to be notified

Does e-invoicing apply to me?

It applies if your aggregate turnover under one PAN exceeded ₹5 crore in any financial year from 2017-18 onwards — and it continues even if turnover later drops. The exempt categories in the table above are out whatever their turnover.

Which documents need an IRN?

• Tax invoices to registered persons (B2B), including supplies on which the buyer pays tax under reverse charge
• Exports and supplies to SEZ units and developers, with or without payment of tax
• Credit notes and debit notes against those invoices

Not covered today: B2C invoices, bills of supply (exempt or composition supplies), delivery challans, and self-invoices for reverse charge on purchases from unregistered persons — though the GST Council has recommended bringing those self-invoices in (see below).

How does e-invoicing work day to day?

1. Your accounting software, or the free tools on the e-invoice portal for small volumes, prepares the invoice in the prescribed format.
2. It is sent to an IRP — NIC's is the most used, and several other IRPs are authorised.
3. The IRP validates it, generates the IRN, signs it and returns a QR code.
4. You print the IRN and QR code on the invoice and give it to the customer.
5. The details flow into your GSTR-1, and reach the buyer's GSTR-2B once your GSTR-1 is filed; with transport details they also feed the e-way bill.

An IRN can be cancelled within 24 hours of generation, and not at all if an active e-way bill exists for it. After that, the only correction is a credit or debit note.

What is the 30-day rule?

Taxpayers with aggregate turnover of ₹10 crore or more must report an invoice to the IRP within 30 days of the invoice date; the portal rejects anything older. The limit started at ₹100 crore on 1 November 2023 and was lowered to ₹10 crore from 1 April 2025. Below ₹10 crore there is no time limit as of now, but generating the IRN when you raise the invoice avoids trouble if the threshold comes down.

What is the penalty for not issuing an e-invoice?

• An invoice that should have an IRN but does not is not a valid tax invoice, so your customer's input tax credit can be denied — usually the first consequence you hear about.
• Penalty of ₹10,000 or the tax evaded, whichever is higher, for issuing an invoice in breach of the rules (section 122(1)(i)), and the general penalty of up to ₹25,000 for other breaches (section 125). The GST Council has recommended lowering the latter to ₹10,000 for e-invoicing lapses; that is not yet law.
• Goods moving without a valid invoice can be detained in transit.

What did the GST Council recommend in October 2026?

At its 57th meeting on 8 October 2026 the Council recommended extending e-invoicing to reverse-charge self-invoices on purchases from unregistered persons and on imports of services, for taxpayers above ₹5 crore. GSTN's advisory of 16 October 2026 says the IRPs are being prepared and the start date will be notified. Until a notification is issued, nothing changes; watch our government updates.

A checklist for the first month

• Confirm your turnover for every year since 2017-18, including exempt and export turnover.
• Enable e-invoicing on the portal and register your GSTIN on the IRP.
• Test your software's output in the sandbox before the go-live date.
• Update your invoice template to show IRN, acknowledgement number and date, and QR code.
• Train the person raising invoices: no IRN, no invoice.
• Reconcile IRP data with GSTR-1 each month.

The compliance calendar lists the monthly GST return dates. New to GST? Start with GST registration for MSMEs; if a notice arrives, see GST notices explained. Approaching ₹5 crore? Our GST services set up e-invoicing and monthly reconciliation — ask our expert team.