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GST Compliance

e-Invoice Guide — Electronic Invoicing under GST

e-Invoicing is the system where B2B invoices are electronically authenticated by the GST Network through the Invoice Registration Portal (IRP). Every B2B invoice gets a unique IRN (Invoice Reference Number) and a digitally signed QR code — enabling real-time reporting, reducing fraud, and auto-populating GSTR-1.

Current Threshold
₹5 Cr+ T/O
Unique ID
IRN (64 chars)
Portal
einvoice1.gst.gov.in
Applies To
B2B Invoices

What is e-Invoicing?

e-Invoicing is NOT a government-generated invoice. You continue creating invoices in your own billing/ERP software. The invoice data is then reported to the IRP in a standardized JSON format. The IRP validates it, generates an IRN, digitally signs the invoice, and returns it with a QR code.

Who must generate e-Invoices? All GST-registered businesses with aggregate annual turnover exceeding ₹5 crore (in any preceding financial year from 2017-18 onwards) must generate e-Invoices for all B2B supplies, including exports and supplies to SEZ. B2C invoices, imports, and reverse charge supplies are excluded.

Penalty for non-compliance: An invoice issued without an IRN when e-Invoicing is mandatory is treated as if no invoice was issued — attracting 100% of tax or ₹10,000 (whichever is higher) as penalty. Additionally, the buyer cannot claim ITC on non-compliant invoices.

e-Invoice Threshold Timeline

1
Oct 2020₹500 Cr+

Phase 1 — Large enterprises

2
Jan 2021₹100 Cr+

Phase 2

3
Apr 2021₹50 Cr+

Phase 3

4
Apr 2022₹20 Cr+

Phase 4

5
Oct 2022₹10 Cr+

Phase 5

6
Aug 2023₹5 Cr+

Phase 6 — Current threshold

How e-Invoicing Works — Step by Step

1

Generate Invoice in ERP/Billing Software

Create a B2B invoice with all mandatory fields — GSTIN, HSN codes, taxable value, tax rates, place of supply, and document type.

2

Push to Invoice Registration Portal (IRP)

Your software sends the invoice JSON to the IRP (einvoice1.gst.gov.in). The IRP validates the schema, checks for duplicates, and generates a unique IRN (Invoice Reference Number).

3

Receive IRN + QR Code + Signed Invoice

IRP returns the digitally signed invoice with a 64-character IRN, QR code (containing key invoice details + digital signature), and acknowledgment number.

4

Auto-Population of GSTR-1 & e-Way Bill

The IRP pushes invoice data to the GST portal (auto-populating GSTR-1) and the e-Way Bill portal (auto-generating Part A of e-Way Bill for invoices > ₹50,000).

5

Share with Buyer

Send the e-Invoice (with QR code and IRN) to the buyer. The buyer can verify the invoice authenticity on the GST portal using the IRN or QR code.

Key Mandatory Fields in e-Invoice

Document Type: INV (Invoice), CRN (Credit Note), DBN (Debit Note)
Supplier GSTIN: 15-digit GSTIN of the supplier
Recipient GSTIN: 15-digit GSTIN of the buyer (for B2B)
Document Number: Unique sequential invoice number (max 16 chars)
Document Date: Invoice date in DD/MM/YYYY format
HSN Code: 4/6/8-digit HSN code per item
Item Value & Tax: Taxable value, IGST/CGST/SGST rate and amount
Place of Supply: State code of supply (determines IGST vs CGST+SGST)

e-Invoice FAQs

Can I cancel an e-Invoice?

Yes, but only within 24 hours of IRN generation on the IRP. After 24 hours, you must issue a credit note against the original e-Invoice. The cancelled IRN cannot be reused.

Is e-Invoice required for B2C transactions?

No. e-Invoicing is mandatory only for B2B, B2B-SEZ, export invoices, and deemed exports. B2C supplies are exempt. However, the QR code requirement on B2C invoices (for businesses with T/O > ₹500 Cr) is a separate provision.

What happens if the IRP is down?

The government has provisioned 4 IRPs for redundancy. If all are down, invoices can be generated offline with a unique document number and uploaded within 24 hours once IRP is back online. The invoice date remains the original date.

Does e-Invoice replace GSTR-1?

Partially. e-Invoice data auto-populates GSTR-1 for B2B invoices. However, B2C supplies, nil-rated supplies, HSN summary, and document summary still need to be entered in GSTR-1 manually.

What is the time limit for generating IRN?

From November 2023, IRN must be generated within 30 days of the invoice date for businesses with T/O > ₹100 crore. For others, there is no explicit time limit, but it should be done before filing GSTR-1.

Generate e-Invoices Directly from Laabam.One

Create invoices → auto-push to IRP → get IRN + QR → auto-populate GSTR-1. All in one click.

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