How it works · 6 min read
IRN and QR Codes on Nigerian E-Invoices, Explained
Every validated Nigerian e-invoice carries two things a normal invoice never had: an Invoice Reference Number (IRN) and a QR code. They are what turn an ordinary invoice into the legally recognised record of a sale. Here is what each one is and where it comes from.
The IRN: the invoice's official identity
The Invoice Reference Number is a unique identifier the NRS system assigns to an invoice once it passes validation. It ties that specific invoice to a specific business and date, so it cannot be duplicated or quietly altered later.
Because the IRN is issued only after validation, its presence is the signal that an invoice is compliant. An invoice without a valid IRN has not been through the system.
The QR code: validation anyone can check
The QR code is a scannable version of the invoice's key details and its validation status. A buyer, auditor or officer can scan it to confirm the invoice is genuine without calling anyone.
This matters for buyers too: scanning the code is how they confirm the invoice they received is the validated one, which is important when they need it for their own records.
What gets created at validation
Alongside the IRN and QR code, the system produces a cryptographic stamp and a digital authentication stamp. Together these protect the invoice against tampering and prove it came through the official channel.
Where the business fits in
Your software prepares the invoice in the required structured format and submits it for validation. When the IRN and QR code come back, your software must place them on the final invoice document the customer receives and keep them in your records.
Getting this flow right, including handling the cases where validation fails and must be retried, is the core of a reliable e-invoicing integration.
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