Belgium Reaches One Million Peppol Recipients: Successful Adoption of Standardized E-Invoicing

The Strategy: Adopting, Not Reinventing

Comparing adoption rates requires context. While Poland has a larger economy, its lower Peppol adoption stems from a different regulatory approach (centralized KSeF model) compared to Belgium's decentralized Peppol-first strategy

A key driver of this success is the Belgian government's decision to leverage established international standards (Peppol) instead of developing a bespoke, centralized national platform immediately. By adopting the Peppol interoperability model, Belgium ensured that its transition to mandatory B2B e-invoicing (effective on January 1, 2026) benefited from a proven, global infrastructure.

The impact of this pragmatic approach is evident in the numbers:

• Surging Adoption: The number of registered entities has increased by more than 54% since December 1, 2025.
• Widespread Readiness: As of late January 2026, registration data shows that nearly 80% of companies in Flanders and approximately 70% in Wallonia and Brussels now hold a Peppol ID.
• Hidden Volume: While registration is mandatory for recipients, invoice issuers are not required to be listed in the central directory, meaning the actual number of Belgian entities active on the network is likely significantly higher.

Understanding the 4-Corner Model

Belgium’s current framework relies on the 4-corner Peppol model, which facilitates seamless data exchange through certified intermediaries.

Under this model, the buyer and supplier exchange invoices via an Access Point. These Access Points are certified service providers, such as Comarch, that ensure every transaction meets strict security and compliance requirements. This includes the use of the UBL 2.1 (Universal Business Language) format and the AS4 communication protocol to guarantee technical interoperability.

Key Deadlines and Compliance

While the mandate is live, the Oman Tax Authority (OTA) and similar global bodies often look to Belgium’s "soft landing" as a blueprint.

• Grace Period: Belgian authorities have implemented a three-month grace period ending in March 2026.
• Penalties: Following this period, full enforcement will begin. Non-compliant businesses may face administrative fines starting at €1,500 for a first offense, rising to €5,000 for subsequent violations.
• Future Roadmap: Belgium plans to evolve toward a 5-corner model from 2028, adding near real-time transaction reporting to the tax authorities — a move toward centralized clearance built on top of the current Peppol-based exchange, not a replacement of the Peppol ecosystem.

Comarch, Your Certified Partner for E-Invoicing in Belgium

As a certified Peppol Access Point, Comarch provides the necessary infrastructure to help your business navigate the Belgian mandate and beyond. Our solution automates the conversion of data into the required Peppol BIS 3.0 format, ensuring your invoices are compliant, secure, and delivered instantly across the network.

Get the full picture of e-invoicing in Belgium – learn more about the new and upcoming regulations.