The Gold Standard for
FIRS e-Invoice Integration

Ensure 100% compliance with the National Revenue Service Management and Billing System (NRSMBS). Our enterprise-grade middleware connects your ERP directly to FIRS.

1.4M+
Invoices Cleared
100%
FIRS Compliant
5k+
Active Taxpayers
90.8%
API Uptime

Who Needs This Integration?

Solutions tailored for every stage of business growth.

Small Businesses

Save time and avoid costly compliance mistakes.

Growing Enterprises

Scale efficiently with automated tax processes.

Large Organization

Streamline compliance and avoid costly errors at scale.

Accountants

Simplify client tax submissions and record management.

Integration Methods

Choose the path that fits your technical infrastructure.

File Upload Portal

Already generating invoices elsewhere? Simply upload your Excel/CSV invoices to our secure portal. We handle the formatting, fiscalisation, and direct submission.

Webhook / API

For businesses that need automation at scale, we offer webhook/API support to connect your existing system directly to FIRS for real-time transmission.

Why Choose Excellium?

The trusted partner for Nigerian tax compliance.

Deep Expertise

We specialize in accounting solutions tailored to Nigerian tax laws.

Intuitive Design

Our integration is simple to use, no matter your business size or technical skill level.

Reliable Support

Our dedicated team is here to assist with setup and troubleshooting.

Top Security

Your data is protected with advanced encryption during every transaction.

FIRS Compliance
Checklist

Our platform automatically handles all technical requirements mandated by the Federal Inland Revenue Service.

✓
Unique IRN Generation

Every invoice receives a unique Invoice Reference Number.

✓
Cryptographic Digital Signatures

Ensures the authenticity and integrity of every tax document.

✓
QR Code Embedding

Instant verification for customers and tax officials via mobile.

ERP Connectors

  • 🔹 ERPNext & Odoo
  • 🔹 Sage 50 / Sage 300
  • 🔹 QuickBooks Online
  • 🔹 SAP Business One

Common Questions

What is the deadline for compliance? +
FIRS is rolling out the mandate in phases. Large taxpayers are already required to comply, while other sectors are being onboarded throughout 2025.
Does this replace my current accounting software? +
No. Our solution acts as a "bridge". You continue using your existing software, and we handle the secure transmission to FIRS.
Is my data secure? +
Yes. We use AES-256 encryption for all data at rest and TLS 1.3 for all data in transit.
Does the system support multi-branch operations? +
Yes. Excellium supports multi-branch setups under a single TIN. Each branch can have its own sub-account while remaining consolidated for tax reporting.
How do I correct an error on a submitted invoice? +
The system allows for the issuance of Credit or Debit notes that are also transmitted to FIRS in real-time to adjust the original submission correctly.
What support is provided during onboarding? +
Our team provides full technical assistance, including API mapping, ERP configuration, and a dedicated account manager to ensure your first submission is successful.

Avoid Penalties. Start Today.

Get your business FIRS-ready in as little as 2 weeks with our expert implementation team.

Contact Us