Tax & Compliance

GST E-Invoicing in India — Threshold, IRN, and How It Works in 2026

GST e-invoicing is the system where B2B invoices above the prescribed turnover threshold are validated by the government's Invoice Registration Portal (IRP) before being issued. Each validated invoice receives a unique Invoice Reference Number (IRN) and QR code from IRP.

Introduced in October 2020, GST e-invoicing aims to standardise B2B invoicing across India. The process: businesses generate invoices in their accounting software (Zoho Books, Tally, ClearTax, SAP) → invoice data sent to IRP via API → IRP validates, digitally signs, returns IRN and QR code → final invoice (with IRN + QR) issued to customer. The threshold has been progressively lowered: ₹500 crore (Oct 2020), ₹100 crore (Jan 2021), ₹50 crore (Apr 2021), ₹20 crore (Apr 2022), ₹10 crore (Oct 2022), ₹5 crore (Aug 2023 onwards). As of 2026, businesses with aggregate annual turnover above ₹5 crore in any preceding FY must e-invoice.

Threshold: ₹5 crore aggregate annual turnover (as of 2026)
Applicable to: B2B invoices, export invoices, credit/debit notes
IRN: 64-character unique identifier from IRP
QR code: contains invoice essentials for offline verification
Not applicable to: B2C invoices, banks, insurers, GTA, SEZ developers/units

Industries served: All Indian B2B businesses above ₹5 crore turnover, SaaS, Manufacturing, IT Services, Distribution, Trading, Exports

Related terms: Invoice Reference Number (IRN), GSTR-1, E-way Bill, GST Portal, Invoice Registration Portal (IRP)

Frequently Asked Questions

Is GST e-invoicing mandatory for my Indian business?

Mandatory if your aggregate annual turnover (across all GSTINs of your PAN) exceeded ₹5 crore in any preceding financial year from FY 2017-18 onwards. Once you cross the threshold, e-invoicing applies from the next financial year onwards — and continues even if turnover later drops below ₹5 crore.

How does GST e-invoicing actually work technically?

Your accounting software (Zoho Books, Tally, etc.) integrates with GSTN's Invoice Registration Portal via API. When you create a B2B invoice: software sends invoice JSON to IRP; IRP validates structure, business details, and uniqueness; IRP returns signed JSON with IRN and QR code; your software prints the final invoice with IRN + QR for the customer.

What software supports GST e-invoicing in India?

Major options: Zoho Books (native), Tally Prime (native), Marg ERP (native), ClearTax (specialist for high-volume), BUSY (native), SAP B1 (with India localisation). Each integrates with GSTN portal via API. For high-volume businesses (5,000+ invoices/month), ClearTax is most reliable; for SMBs, Zoho Books or Tally are standard.

What happens if I don't generate IRN for invoices above threshold?

The invoice is not legally valid for GST purposes. Buyer cannot claim ITC. You may face penalty + interest. Worse, your subsequent GSTR-1 may show inconsistencies that trigger GST audit. Always generate IRN for B2B invoices once your turnover crosses ₹5 crore.

Do I need IRN for B2C invoices?

No. E-invoicing is mandatory only for B2B (business-to-business) transactions, exports, and credit/debit notes. B2C invoices, bank statements, and certain exempted categories do not require IRN. For B2C-heavy businesses (retail, e-commerce direct to consumer), most invoices don't need e-invoicing.

Set up GST e-invoicing for India — Zoho Books or Tally configured with GSTN API.