GST e-Invoicing Compliance & IRN

E-invoicing under Rule 48(4): B2B invoices must be submitted to the Invoice Registration Portal (IRP — managed by NIC and private IRPs) in the prescribed JSON schema. The IRP generates a unique IRN (Invoice Reference Number — a 64-character hash) and a QR code, and returns the signed e-invoice. The signed JSON must be reproduced on the physical/digital invoice. IRN is valid for 24 hours — after which the invoice cannot be cancelled on the IRP (only on the buyer-seller level).

Mandatory for: taxpayers with aggregate turnover > ₹5 crore from 1 August 2023; > ₹10 crore from 1 October 2022; > ₹20 crore from 1 April 2022; > ₹50 crore from 1 April 2021; > ₹100 crore from 1 January 2021; > ₹500 crore from 1 October 2020. Exclusions: banking companies, financial institutions, NBFCs, GTA, and passenger transport operators — their invoices are excluded from e-invoicing. SEZ units are included (effective 1 October 2020).

An invoice issued without IRN when e-invoicing is mandatory is not a valid GST invoice under Rule 48(4). Consequence: the buyer cannot claim ITC (Section 16(2)(a) requires a valid invoice). The supplier faces a penalty under Section 122(1)(a) — ₹10,000 or tax amount, whichever is higher, per invalid invoice. E-invoicing errors also result in GSTR-1 auto-population failures — requiring manual correction with retrospective IRN where possible.

E-invoices auto-populate in GSTR-1 — once an IRN is generated, the invoice details are available in the supplier's GSTR-1 (Table 4A for registered recipients). The supplier does not need to separately enter e-invoice details in GSTR-1. However, the supplier must still review and file GSTR-1 — auto-population does not equal auto-filing. Errors in the e-invoice (wrong GSTIN, wrong amount) must be corrected by cancelling the IRN within 24 hours and generating a new one.

Cancellation: an IRN can be cancelled only within 24 hours of generation, if no e-way bill has been generated against it. Post-24-hours: the invoice cannot be cancelled on the IRP — the supplier must issue a credit note under Section 34 to reverse the supply. Amendment: the IRP does not support amendment of a generated IRN — cancel within 24 hours and re-issue. Post-24-hours: GSTR-1 amendment in the next return period is the only mechanism, subject to the time limit under Section 16(4).