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E-Invoicing Under GST: Who Needs It & How to Generate It

E-invoicing is mandatory for businesses above ₹5 crore turnover. Learn how IRP works, the process for generating IRN and QR code, and the benefits of e-invoicing.

7 min read Updated 15 March 2026 Kallapotti Editorial Team
E-InvoiceIRNIRPGSTINQR CodeGST

E-invoicing under GST requires eligible businesses to report B2B invoices to the government's Invoice Registration Portal (IRP) in real time, receive an Invoice Reference Number (IRN), and include it on all invoices.

Who Must Generate E-Invoices?

Aggregate TurnoverE-Invoice Mandatory From
> ₹500 Crore1st October 2020
> ₹100 Crore1st January 2021
> ₹50 Crore1st April 2021
> ₹20 Crore1st April 2022
> ₹10 Crore1st October 2022
> ₹5 Crore1st August 2023

How E-Invoicing Works

  1. 1 Create the invoice in your billing software (like Kallapotti)
  2. 2 System sends invoice data as a JSON file to the IRP (einvoice1.gst.gov.in)
  3. 3 IRP validates, generates a unique IRN (Invoice Reference Number) and QR Code
  4. 4 IRN is returned to your system and embedded on the invoice
  5. 5 Invoice is shared with buyer with IRN + QR code printed on it
  6. 6 IRP auto-populates GSTR-1 — no manual data entry needed

Key Benefits

  • Auto-populates GSTR-1 — eliminates manual data entry
  • Reduces fake invoices and ITC fraud
  • Buyers can verify invoice authenticity by scanning QR code
  • Faster ITC matching since data flows directly to GSTR-2B
  • E-way bill auto-generated for applicable supplies
Important

E-invoices must be generated BEFORE goods are dispatched. A valid IRN is required. Missing or invalid e-invoices can attract a penalty of ₹10,000 per invoice under Section 122.

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