GST E-Invoicing Infrastructure

Under India’s GST e-invoicing rules, qualifying invoices must be registered with the Invoice Registration Portal. The registration returns an invoice reference number (IRN) and a signed QR code that belong on the final invoice.

I led a direct integration with the IRP so registration happens inside the existing Django billing flow.

• The IRN and signed QR data returned by the portal must reach the customer’s invoice unchanged.
• Registration depends on an external government service, so the billing flow has to cope with it being slow or unavailable.
• Tax and customer data must never appear in logs, examples or demos.

• A direct IRP API integration that registers invoices from the billing workflow.
• Handling of the returned IRN and signed QR data.
• Customer-ready PDF invoices that carry the registration details, sent to customers by email.

Calling the portal directly means owning authentication and error handling for an external service. It removes the export, upload and re-import loop and keeps the invoice and its registration together.

E-invoicing runs as part of billing instead of as a separate manual step.