When a GST tax invoice must carry an IRN and QR code — the ₹5 crore e-invoicing threshold

Above a turnover threshold, a GST tax invoice is no longer something a business can simply print — it must be registered with a government portal first. This is **e-invoicing**, and Rule 48(4) of the CGST Rules makes it mandatory for businesses over the threshold. The flow above shows the two tests — turnover and supply type — that decide whether a given invoice needs an Invoice Reference Number.

The first test is **turnover**: e-invoicing applies to a registered person whose **aggregate turnover crossed ₹5 crore in any financial year from 2017-18 onward**. The ₹5 crore figure is the current threshold, brought in by CBIC Notification 10/2023-Central Tax with effect from 1 August 2023 — the limit has stepped down over time from ₹500 crore at launch. The "any year since 2017-18" wording matters: once a business crosses ₹5 crore in even one year, it stays in the e-invoicing net even if a later year falls below.

The second test is the **type of supply**. E-invoicing applies to **B2B supplies, supplies to SEZ, exports, and supplies under reverse charge** — broadly, transactions where the recipient can claim credit. It does **not** apply to **B2C supplies**; a consumer sale by an over-threshold business does not need an IRN (a separate dynamic-QR requirement can apply to large B2C suppliers, but that is a different rule). Where both tests are met, the supplier must upload the invoice to the **Invoice Registration Portal (IRP)** *before* issuing it; the IRP validates the data and returns an **Invoice Reference Number (IRN)** and a **digitally signed QR code**, which must be printed on the invoice given to the buyer.

The consequence of getting this wrong is sharp. Rule 48(5) states that an invoice which *should* carry an IRN but does not **is not a valid tax invoice at all**. For the buyer that means the input tax credit on a non-compliant invoice is exposed, and for the supplier it attracts a penalty for issuing an incorrect invoice. So for an over-threshold B2B supplier the e-invoicing step is not an add-on — it is what makes the document a tax invoice in the first place. Below ₹5 crore, none of this applies and the ordinary Rule 46 tax invoice stands on its own.