Who must issue e-invoices under GST, and what is the 30-day rule?

Who is covered

Every registered person whose aggregate turnover, for all GSTINs under the same PAN, exceeded ₹5 crore in any financial year from 2017-18 onwards. Once you cross the limit, you stay covered even if turnover falls later.

Exempt whatever their turnover: SEZ units (not developers); insurers, banks, NBFCs and other financial institutions; goods transport agencies; passenger transport services; admission to cinema in multiplex screens; and government departments and local authorities.

Which documents

• Tax invoices for supplies to registered persons (B2B), including SEZ units and deemed exports.
• Exports.
• Credit and debit notes for these.

Supplies to consumers (B2C) are not e-invoiced. Very large businesses (turnover above ₹500 crore) must instead print a dynamic QR code on B2C invoices.

How it works

1. Prepare the invoice in your billing software and upload it, as JSON, to an Invoice Registration Portal (IRP).
2. The IRP returns an Invoice Reference Number (IRN), a digital signature and a signed QR code. Print the QR code on the invoice.
3. The details flow into your GSTR-1 and, with transport details, into Part A of the e-way bill.

An IRN can be cancelled within 24 hours; after that, issue a credit note. It cannot be edited on the IRP; corrections are made in GSTR-1 before filing.

The 30-day limit

Since 1 April 2025, a taxpayer with aggregate turnover of ₹10 crore or more cannot report an invoice or note older than 30 days from its date. The IRP rejects it. Report invoices on the day you issue them.

Consequences of not complying

• The document is not a valid tax invoice, so the buyer cannot claim input tax credit.
• A penalty can be levied for each invoice.
• Goods may be detained in transit if the e-way bill does not match.