PEPPOL OutBox: a dedicated PEPPOL outbox, custom mappings, and significantly fewer errors

Since 2024, electronic invoicing via the PEPPOL network has become mandatory in Belgium.
On paper, the objective is clear: to standardize, automate, and secure invoice exchanges.

For Belgian companies, the real issue isn't the regulation itself. The challenge lies in adapting existing, and often complex, systems to a strict standard without creating friction, requiring heavy overhauls, or increasing errors.

At KERN IT, we designed PEPPOL OutBox to address a very specific challenge:

To sustainably reduce PEPPOL errors by adapting to existing systems through fully custom mapping, while centralizing all outgoing invoices in a single outbox.

PEPPOL Compliance vs. the Reality of Belgian Companies

Many solutions on the market claim to be "PEPPOL-ready."
They work perfectly in simple environments, with a single tool and standardized processes.

But many Belgian companies operate differently:

• One or more internal invoicing tools
• Custom-built ERPs or business software
• Multiple business units with their own specific constraints
• Several legal entities within the same group
• Recurring and growing invoice volumes

In these contexts, PEPPOL compliance becomes a matter of architecture and reliability, rather than a simple question of software compatibility.

When volumes transform a technical detail into a structural risk

At low volumes, minor inaccuracies may go unnoticed.
As volumes increase, they become structural.

Rejections.
Manual corrections.
Unstable workflows.
Lack of visibility.

👉 As volumes increase, every error repeats.

PEPPOL is not the cause of this situation.
The issue lies in applying generic mappings to systems that are anything but generic.

The real question for leaders

The question is not:

"Are we capable of sending invoices via PEPPOL?"

The real question is:

"How can we guarantee stable, reliable, and sustainable PEPPOL compliance, without multiplying errors as our volumes, tools, and organization evolve?"

PEPPOL OutBox in 3 simple steps

PEPPOL OutBox was designed to remain easy to understand, even in complex environments.
Its operation is based on three clear steps, which remain identical regardless of your volume or organization

1. Your systems generate the invoices

Your ERPs, business software, or internal tools continue to operate exactly as they do today. They generate invoices in their existing formats, without any process modifications.

No changes for your teams.
No forced migrations.

2. Fully custom mapping transforms your data

Each flow is analyzed and transformed via a mapping developed specifically for your system and your business reality.

This mapping allows you to:

• Faithfully translate your data to the PEPPOL standard
• Avoid generic interpretations
• Significantly reduce rejections and sending errors

👉 Custom mapping is the primary lever for reducing errors.

3. A single OutBox sends to the PEPPOL network

Once transformed, invoices are sent over the PEPPOL network via a certified Access Point.

PEPPOL OutBox becomes:

• Your unique exit point
• Your tracking center for statuses and receipts
• Your PEPPOL compliance layer

Even if you have multiple tools, business units, or companies.

Centralize PEPPOL sending, not your systems

Many companies aren't looking to unify their business tools.
Instead, they want:

• A single control point for compliance
• A consolidated view of all outgoing invoices
• Clear traceability for audits
• Consistent management of statuses and rejections

Centralizing PEPPOL output means centralizing responsibility and compliance, without consolidating systems or imposing a single platform.

The core value: custom mapping

The reliability of PEPPOL OutBox is based on one fundamental principle:

Every mapping is custom-developed, specifically for your system and your organization.

Your invoices can be generated in PDF, XML, JSON, CSV, Excel, or proprietary formats.
PEPPOL imposes a strict standard.

The role of PEPPOL OutBox is not to "roughly adapt" your data to PEPPOL.
Its role is to faithfully translate your business reality into this standard.

Less automatic interpretation.
Fewer errors.
Fewer rejections.

Multi-tool, multi-business unit, multi-company

PEPPOL OutBox is designed for complex organizations:

• Multiple invoicing tools
• Multiple business units
• Multiple legal entities
• Multiple PEPPOL identities

Each flow features:

• Its own custom mapping
• Its own business logic
• Its own tracking

All processed through a single PEPPOL OutBox.

An architecture designed for stability and scalability

PEPPOL OutBox is designed to perform over time:

• REST API for automated sending
• Webhooks for acknowledgments
• Tracking by invoice, system, and company
• Native multi-company management
• Sending via a certified PEPPOL Access Point
• Compliance and management dashboard

Whether volumes grow or the organization evolves, the principle remains the same: a controlled, stable, and predictable workflow.

Who is PEPPOL OutBox for?

PEPPOL OutBox is for:

• Belgian SMEs
• Mid-sized companies
• Multi-entity groups
• Organizations with in-house ERPs or business software
• Entities invoicing regularly or in high volumes

This is not a mass-market solution.
It is a solution designed for the operational reality of Belgian companies.

A solution developed in Belgium by KERN IT

PEPPOL OutBox is a product developed by KERN IT, a Belgian company specialized in custom development and complex systems integration.

Our approach is intentionally pragmatic:

• Respect existing systems
• Adapt compliance to business reality
• Reduce errors rather than fixing them after the fact
• Build sustainable and controlled solutions

Conclusion

PEPPOL is not a one-off project.
It is a permanent workflow that settles in over time.

The sooner your PEPPOL output is stabilized with custom mapping, the less it remains an operational burden.

For Belgian companies looking to:

• Centralize their PEPPOL transmissions
• Sustainably reduce errors
• Preserve their existing systems
• Support seamless scaling

👉 PEPPOL OutBox is not just another tool.
It is the PEPPOL outbox your systems have been waiting for.

Learn more

https://peppol-outbox.be/