E-Invoicing in Belgium: B2B Mandate from 2026, Peppol-Network and EN 16931 Explained

Starting January 1, 2026, electronic invoicing (E-Invoicing) will be mandatory for all domestic business-to-business (B2B) transactions between value-added tax (VAT)-registered companies in Belgium. Businesses with an active Belgian VAT number must issue, receive, and process structured electronic invoices.

This obligation is based on the Royal Decree of July 8, 2025, which establishes the binding framework for E-Invoicing in Belgium. Traditional invoice formats, such as paper or PDF invoices, will no longer be accepted. Starting in 2026, electronic invoices will be exchanged directly between business partners' ERP and IT systems via the PEPPOL (Pan-European Public Procurement Online) network. Currently, only B2B e-invoicing is mandatory. Direct reporting to tax authorities is planned to begin on January 1, 2028.

All B2B E-Invoices must comply with the European standard EN 16931 to ensure standardized, secure, and fully automated cross-system processing.

Who Is Affected by E-Invoicing in Belgium Starting in 2026?

The requirement applies to all VAT-registered businesses conducting transactions with other companies in Belgium. This includes Belgian companies, Belgian branches of foreign businesses, and members of Belgian VAT groups.

According to the Belgian Federal Public Service Finance (FPS BOSA), all entities with a valid VAT number must issue and receive electronic invoices. Businesses that only issue invoices to private consumers (B2C) are exempt from this obligation. However, they must be able to receive structured electronic invoices from their suppliers and ensure that their systems are updated by January 2026.

How Does Electronic Invoicing via Peppol Work?

Belgium is implementing E-Invoicing through the well-established PEPPOL (Pan-European Public Procurement Online) network. This system enables the secure, decentralized, standardized exchange of structured invoice data between ERP and accounting systems of business partners.

A company's invoicing or accounting software establishes a secure connection to the Peppol network, which is also used by its business partners. Instead of sending invoices as files, Peppol transmits invoice data as structured, standardized datasets. This allows invoices to be automatically validated, verified, and posted.

Companies must ensure their systems are compatible with Peppol BIS 3.0, capable of creating and sending invoices, and able to receive invoices in compliance with EN 16931. This technical framework is a key component of Belgium's E-Invoicing requirements and supports automated, interoperable invoice processing across the EU.

What Are Belgium's Requirements for Structured E-Invoices?

To be considered valid in Belgium, an E-Invoice must contain all the mandatory fields defined by the European standard EN 16931. These include the invoice number, invoice date, buyer and seller identifiers, tax details, VAT rates, and payment terms.

Starting January 1, 2026, new rounding rules will also apply. It will only be permitted to round the total amount by VAT category, not at the line-item level. Businesses must update their systems accordingly to ensure accurate calculations and presentations. Failure to comply may result in technical penalties imposed by the Belgian administration, as outlined in the Royal Decree of July 2025. Therefore, companies are advised to validate their e-invoicing systems and review their processes for compliance.

What Steps Should Businesses Take to Prepare for Belgium’s Upcoming E-Invoicing Mandate?

Companies that already use EDI or API-based solutions can adapt their current systems to meet the new legal requirements. The key is ensuring that current integrations fully support the data structure defined in EN 16931 and are connected to the Peppol network.

A technical readiness check is highly recommended:

1. Are your systems Peppol-enabled?

2. Do they capture all required data fields?

3. Are automated validation and approval workflows in place?

With E-Invoicing, data quality is critical to success. Incorrect VAT numbers or incomplete master data can result in invoice rejections and delayed payments. Therefore, ensuring clean, accurate, and complete data across all systems is essential for smooth compliance and uninterrupted cash flow.

What's Coming in 2028: E-Reporting in Belgium

Starting in 2028, Belgium will implement an additional e-reporting system that will allow for the near real-time transmission of invoice data to tax authorities. This new requirement supplements the mandatory E-Invoicing rules set to take effect in 2026.

Aligned with the European "VAT in the Digital Age" (ViDA) initiative, the model aims to reduce VAT fraud, close the VAT gap, and simplify administrative processes. In the long term, businesses will benefit from greater transparency and reduced reporting obligations, which will lower their administrative burden.

E-Invoicing in Belgium: A Driver for Digital Transformation

The introduction of E-Invoicing marks a major milestone on Belgium’s path toward a fully digital tax administration system. Beginning in 2026, structured electronic invoicing will be both a legal requirement and the new standard for modern business communication.

Companies that adopt Peppol, EN 16931, and automated invoicing workflows early on will enjoy lasting advantages in terms of compliance, efficiency, and data accuracy. eddyson enables companies to manage these requirements centrally and at scale, ensuring a future-proof digital invoicing process across the entire supply chain.