What is a GST e-invoice?
A GST e-invoice is a B2B tax invoice whose details are reported to a government Invoice Registration Portal (IRP), which returns an invoice reference number (IRN) and a signed QR code.
Also called e-invoice, e-invoicing, IRN, invoice reference number.
E-invoicing does not mean the government writes your invoice. You still make the invoice in your own software; you upload its details in the notified format to an IRP, and the IRP validates them, signs them and returns the IRN and a QR code to print on the invoice. The data then flows into your GSTR-1. GSTN lists six IRPs, and reporting on them is free.
The rule. Rule 48(4) of the CGST Rules, 2017 requires notified persons to prepare invoices with the particulars of Form GST INV-01 after obtaining an IRN. Under rule 48(5), an invoice they issue any other way is not treated as an invoice.
Who must do it. Notification 13/2020-Central Tax, as amended (latest by Notification 10/2023-Central Tax, from 1 August 2023), covers registered persons whose aggregate turnover in any financial year from 2017-18 onwards exceeds ₹5 crore, for supplies to registered persons and for exports. Turnover is counted across all GSTINs on the same PAN. SEZ units are excluded, as are insurers, banks and other financial institutions, goods transport agencies, passenger transport services and multiplex cinema admissions (rule 54(2) to (4A)).
For a builder above ₹5 crore, this means tax invoices to GST-registered customers, such as a company leasing an office, need an IRN. Invoices to home buyers who are not registered are B2C and outside e-invoicing.
The parts of an e-invoice.
- IRN: a 64-character hash of the supplier’s GSTIN, the financial year, the document type and the document number, unique to that invoice for the whole financial year.
- Signed QR code: the supplier’s and recipient’s GSTINs, invoice number and date, invoice value, number of line items, HSN code of the main item, the IRN and its date, signed by the IRP so anyone can verify it offline.
- Cancellation: whole invoices only, through the IRP within 24 hours of generating the IRN. The same document number cannot be reported again.
The 30-day limit. Since 1 April 2025, taxpayers with annual aggregate turnover of ₹10 crore or more cannot report an invoice, credit note or debit note more than 30 days after its date. Sample: an invoice dated 1 December 2026 cannot be reported after 30 December 2026. A mistake cannot be edited; the only fix is to cancel within 24 hours and report a new document with a new number.
LoftRay’s accounts and tax module has GST e-invoicing built in: it gets the IRN and signed QR from the IRP for B2B tax invoices on demands and lease charges, using the builder’s own e-invoice API credentials, and can cancel within 24 hours.
Sources, read on 9 Nov 2026: CBIC: rule 48, CGST Rules, e-invoice notifications (IRP), Notification 10/2023-Central Tax, GSTN glossary on e-invoicing, e-invoice FAQs and GSTN advisory on the 30-day limit, 5 Nov 2024.