e-Invoicing under GST
e-Invoicing under GST means registering B2B invoices on the government's Invoice Registration Portal (IRP) to obtain a unique IRN and QR code. This guide covers the ₹5 crore threshold, who is exempt, how the IRP mechanism works, penalties and how billing apps automate the flow.
What is e-invoicing under GST?
e-Invoicing is a reporting system, not a new invoice type. You still issue a regular GST invoice to your buyer — but you must first register it on the government's Invoice Registration Portal (IRP). The IRP validates the data, assigns a unique Invoice Reference Number (IRN) and returns a digitally signed QR code that must be printed on the invoice.
The IRP also pushes the invoice data directly into your GSTR-1 and your buyer's GSTR-2B — eliminating data-entry errors and ITC mismatches.
e-Invoicing threshold — ₹5 crore (as of August 2023)
e-Invoicing is mandatory for businesses whose aggregate annual turnover exceeded the applicable threshold in any financial year from 2017-18. The limit has been reduced progressively:
| Effective date | Turnover threshold |
|---|---|
| 1 Oct 2020 | ₹500 crore and above |
| 1 Jan 2021 | ₹100 crore and above |
| 1 Apr 2021 | ₹50 crore and above |
| 1 Apr 2022 | ₹20 crore and above |
| 1 Oct 2022 | ₹10 crore and above |
| 1 Aug 2023 | ₹5 crore and above |
Which documents require e-invoicing?
- B2B tax invoices (including exports and SEZ supplies)
- Credit notes
- Debit notes
B2C invoices do not require e-invoicing. For inter-state B2C supplies above ₹1 lakh, a Dynamic QR Code must be printed — but this is separate from the IRP-generated IRN.
Who is exempt from e-invoicing?
Even above ₹5 crore, these categories are exempt:
- Banks, financial institutions and NBFCs
- Insurance companies
- Goods Transport Agencies (GTAs) issuing consignment notes
- Passenger transport service providers
- Cinema/multiplex/exhibition admission services
- SEZ units (as supplier; SEZ developers are not exempt)
- Government departments for non-commercial purposes
- OIDAR service providers
How IRN and the QR code work
The IRN is a 64-character SHA-256 hash of four fields: Supplier GSTIN, Financial Year, Document Type (INV / CRN / DBN) and Document Number. The same invoice number can never produce a duplicate IRN — and any change to the invoice after IRN generation requires cancellation and re-generation within the 24-hour window.
The signed QR code contains: supplier and buyer GSTINs, IRN, invoice number, date, value, number of line items, main HSN code and digital signature. Anyone can verify by scanning with the GST e-invoice verification app.
End-to-end e-invoicing flow — 5 steps
- Prepare the invoice JSON — in your billing software using the GSTN e-invoice schema: supplier/buyer GSTINs, HSN codes, GST rates, taxable values and tax amounts.
- Upload to IRP — via REST API, bulk offline utility or your billing app's built-in e-invoicing integration (available at einvoice1.gst.gov.inand authorised private IRPs).
- IRP validates — checks active GSTINs and valid HSN codes. Invalid invoices are rejected with an error code.
- Receive IRN and QR code — on success: 64-character IRN, signed JSON and Base64-encoded QR code image. The IRP simultaneously sends data to GSTN for GSTR-1 auto-population.
- Embed on invoice PDF — print the IRN and QR code on every copy. Within 24–48 hours the data appears in your GSTR-1 and buyer's GSTR-2B.
Cancellation and amendment rules
- Cancellation on IRP: allowed within 24 hours of IRN generation only.
- After 24 hours: issue a credit note; report via amendment tables in GSTR-1.
- You cannot amend invoice content after IRN is generated — generate a new IRN with a corrected invoice and a credit note against the original.
Penalties for e-invoicing non-compliance
- ₹10,000 per invoice under Section 122 CGST Act for issuing an invalid invoice.
- 2% of invoice value (up to ₹25,000) under Section 125 for general non-compliance.
- Buyer cannot claim ITC — a direct financial impact on your business relationship.
How billing apps automate e-invoicing
GST billing software integrated with the IRP API fetches the IRN automatically — you raise the invoice and the IRN and QR code are embedded in the PDF before it reaches the buyer. BillRaja generates GST-compliant invoices with the correct CGST/SGST/IGST split and HSN codes — the foundation for e-invoice-ready JSON. Use the GST invoice generator for a complete bill-to-PDF workflow.
Frequently asked questions
Who must generate e-invoices under GST?
What is an IRN and how is it generated?
What happens if I issue a B2B invoice without an IRN?
Who is exempt from e-invoicing?
Can e-invoices be cancelled?
Related tools & guides
GST-compliant invoices, every time.
BillRaja generates invoices with correct CGST/SGST/IGST, HSN codes and invoice numbering — everything you need for GSTR-1 and e-invoicing compliance. Free to start.
