Mastering E-Invoicing in India: The Definitive IRN and B2B QR Code Guide

Understanding Mandatory E-Invoicing in India

The Government of India has systematically lowered the aggregate turnover threshold for mandatory B2B electronic invoicing. Today, businesses exceeding specified turnover thresholds must authenticate all B2B and export invoices through an authorized Invoice Registration Portal (IRP) before dispatching goods or services.

The Anatomy of an E-Invoice

An e-Invoice is not merely a computerized PDF. Under standard schema INV-01, it is a cryptographically validated JSON document containing:

• Invoice Reference Number (IRN): A unique 64-character hash computed using supplier GSTIN, invoice number, and financial year.
• Digitally Signed QR Code: Contains core transaction metadata (seller/buyer GSTIN, invoice date, taxable value, tax components, IRN) for offline validation by tax authorities.
• Digital Signature: Issued by the IRP to certify payload authenticity.

Real-Time API Integration with Relaso

Generating IRNs manually through government bulk utilities causes logistical bottlenecks. With Relaso's Automated E-Invoicing Suite, finalizing an invoice generates the IRN and signed QR code in under 400 milliseconds via direct IRP APIs, printing tax-compliant documents instantaneously.