Technical Rules for E-Invoicing in Belgium

Updated On : Jan 25th, 2026 | 18 min read

Belgium is entering a decisive phase in its digital transformation, driven by the broader European effort to create a unified, efficient and transparent invoicing ecosystem. Structured electronic invoicing will soon become the default format for business-to-business transactions. This change has major implications for how companies generate invoices, exchange documents and maintain VAT compliance.

The rules governing this new system are precise and highly technical, which is why understanding the regulatory expectations early is essential. The following guide breaks down the technical requirements, formats and standards that apply under Belgium`s e-invoicing framework, and explains how businesses can prepare for the transition.

Shift to Mandatory Structured Invoicing from 2026

Starting 1 January 2026, most VAT-registered Belgian businesses will be required to issue and receive structured electronic invoices for all business-to-business transactions. This shift is intended to create a fully automated, end-to-end invoicing process that removes manual work, improves accuracy and enables more reliable VAT monitoring.

Scope of the Mandate

Business-to-Business Transactions

Almost all B2B transactions between Belgian VAT-liable enterprises fall within the mandatory scope.

Business-to-Consumer Transactions

Personal consumer transactions remain outside the requirement, and businesses may continue issuing traditional invoices for B2C customers.

Business-to-Government Transactions

Since 1 March 2024, structured e-invoicing has been compulsory for public procurement contracts above €3,000.

Limited Exemptions

Some entities are exempt, such as bankrupt persons registered for VAT, businesses performing only VAT-exempt operations under Article 44 and flat-rate taxpayers until 2028.

What Makes a Structured Electronic Invoice

A structured electronic invoice is a machine-readable data file. It is not a PDF, not an emailed attachment and not a scanned copy. It is a digital document containing data in a format that accounting systems can interpret without manual intervention.

To comply with Belgian requirements, structured invoices must meet several strict conditions.

Alignment with European Standards

Invoices must follow EN 16931, which defines the semantic structure and technical specifications required for cross-border interoperability within the European Union.

Inclusion of Mandatory Data Fields

Every invoice must include specific information such as the VAT identification of the buyer and supplier, invoice number, invoice date, line items, tax amounts, totals and payment details.

Use of the Peppol BIS Format

Belgium uses the Peppol BIS format as the default structure for transmitting electronic invoices. This format ensures consistency and enables seamless data exchange through the Peppol network.

The Technical Foundations: Authenticity, Integrity and Legibility

Belgium`s e-invoicing framework is built around three core technical principles. These principles ensure that invoices remain reliable, traceable and compliant throughout their entire life cycle.

Authenticity of Origin

The origin of the invoice must always be identifiable. Both supplier and customer share responsibility for ensuring that the invoice genuinely originates from the correct issuer. This requirement helps prevent fraudulent invoices and strengthens VAT control.

Integrity of Content

Once issued, the invoice must remain unaltered. If a correction or amendment is required, it must be made through a separate structured document that references the original invoice. This requirement preserves the reliability of the financial record.

Legibility Over Time

Invoices must remain readable for the entire retention period. For electronic invoicing, this means the file must be retrievable in a clearly readable form at any time, and the displayed version must match the original document.

Electronic Modifications and Referencing

Any modification issued in an electronic format is treated as a structured invoice when it:

1. Follows the same technical structure as the original
2. References the original invoice clearly and accurately

This ensures that the financial and audit history remains consistent, traceable and complete.

Retention and VAT Compliance

Beginning in 2026, structured invoices will serve as the main evidence for VAT deductions and reporting. The familiar reliance on PDF files or paper documents will be replaced by a more precise and auditable framework.

The Audit Trail Requirement

A reliable audit trail is essential. It must demonstrate:

Traceability

A clear link must exist between the invoice and the underlying business transaction.

Compliance with VAT Procedures

The audit trail must reflect the processes mandated by Belgian VAT legislation.

Accuracy of Operational Reality

Documentation must match actual delivery of goods, performance of services and payment processes.

Sending and Receiving Invoices through the Peppol Network

The Peppol network is at the heart of Belgium`s structured invoicing ecosystem. It is an international framework that allows businesses and public authorities to exchange electronic documents securely and consistently.

Sending Invoices

Companies must use software connected to a certified Peppol Access Point. Invoices are created in the Peppol BIS format and sent through the network to the recipient`s system.

Receiving Invoices

Companies must ensure their system can receive structured invoices and interpret them correctly. This often requires an upgrade of accounting software or a dedicated Peppol integration.

Why Peppol is Central to Belgium`s Approach

The Peppol framework brings structure and reliability to electronic invoicing. Its benefits include:

Interoperability Across Borders

Invoices can be exchanged with any business or authority registered on Peppol, regardless of the country.

High Security Levels

Invoices move through certified service providers, drastically lowering the risk of invoice fraud.

Operational Efficiency

Because invoices are delivered in a structured format, automation becomes a natural part of financial workflows.

EN 16931 and Peppol BIS: How They Work Together

Belgium`s technical rules combine a European standard with a network-specific format.

EN 16931

Defines the European standard that dictates which data fields and semantic structures must appear in a structured invoice.

Peppol BIS

Provides a harmonised format that applies these rules in a practical, machine-readable structure.

The combination of both ensures that invoices are compliant, interoperable and ready for automated processing.

Allowed and Prohibited Invoice Formats

Under the upcoming rules, the type of invoice businesses can issue will change significantly.

PDF Invoices

Permitted only until the end of 2025. Starting January 2026, they will no longer be legally valid for B2B VAT invoices.

Word or Excel

Allowed only with the recipient`s approval and only until December 2025.

Structured EN 16931 Compliant Formats

From January 2026 onward, all B2B invoices must be created and transmitted in a structured electronic format that follows Peppol BIS.

Conclusion

Belgium`s e-invoicing reform represents one of the most significant modernisations of the country`s financial and VAT infrastructure. The shift to structured invoicing, enforced through Peppol BIS and EN 16931, is designed to eliminate manual inefficiencies, improve VAT oversight and support cross-border interoperability across Europe. Preparing early is essential. This includes upgrading accounting systems, ensuring software compatibility, training teams and establishing internal processes that support structured invoicing.

As businesses make this transition, many find that dedicated platforms simplify the journey. Solutions such as Accqrate help companies adopt structured invoicing with confidence by supporting the required formats, enabling Peppol connectivity and strengthening compliance workflows in a straightforward and reliable way.