B2G invoicing in Belgium: practical guide for suppliers

B2G invoicing in Belgium: what you need to know

Since 2024, all businesses supplying goods or services to Belgian public administrations are required to send their invoices in electronic format via the PEPPOL network. This is known as B2G (Business-to-Government) invoicing.

If you work with the public sector — whether the federal government, a region, province, municipality or CPAS — this guide is for you.

Who is affected?

All suppliers to the Belgian public sector, regardless of size:

• Self-employed professionals
• SMEs
• Large enterprises
• Non-profit organisations

Whenever you issue an invoice to a Belgian public entity, it must be in structured electronic format (UBL) and transmitted via PEPPOL.

Which administrations accept PEPPOL invoices?

Nearly all Belgian administrations are connected to the PEPPOL network:

Federal level

• FPS Finance
• FPS Economy
• FPS Mobility
• Defence
• Federal Police
• All FPS and PPS

Regional level

• Flemish Region — via Mercurius
• Walloon Region — via the e-FED portal
• Brussels-Capital Region
• French Community and German-speaking Community

Local level

• Municipalities and CPAS (progressively connected)
• Provinces
• Intermunicipal organisations

The required format: UBL-CIUS

B2G invoices in Belgium must comply with the PEPPOL BIS Billing 3.0 format, based on the UBL 2.1 standard. In the Belgian context, this format is also known as e-FFF (electronic Free Format Form).

Specifically, your invoice must contain:

• Mandatory data: invoice number, date, supplier/customer details, invoice lines, VAT amounts
• The BCE/VAT number of the public recipient
• The public procurement reference or purchase order number (often mandatory)
• The GLN code or PEPPOL identifier of the destination administration

Step-by-step guide

Step 1: Register on PEPPOL

Choose a certified Access Point like DIGIPOSA. We register your business on the PEPPOL network within a few days.

Step 2: Prepare your first invoice

In Digiposapp, create your invoice as usual:

• Enter the public administration’s details
• Add the public procurement reference or purchase order
• Detail the invoice lines with appropriate VAT codes

Step 3: Send via PEPPOL

Click “Send”. Digiposapp automatically converts your invoice to UBL format and sends it via PEPPOL. You receive a delivery confirmation.

Step 4: Track the status

Track your invoice processing directly from your dashboard. You are notified in case of rejection or correction request.

Common mistakes to avoid

1. Forgetting the procurement reference

This is the leading cause of rejection. Every invoice to a public administration must contain the procurement reference or purchase order number.

2. Wrong recipient identifier

Always verify that the recipient’s PEPPOL identifier is correct. An error in the BCE number leads to automatic rejection.

3. Incorrect VAT

Public administrations are subject to specific VAT regimes. Check the applicable rate.

4. Non-compliant format

A PDF sent by email is not an electronic invoice in the legal sense. Only UBL format transmitted via PEPPOL is compliant with the B2G obligation.

Benefits for your business

• Faster payment — Public administrations process electronic invoices as a priority
• Fewer disputes — The structured format reduces errors and rejections
• Complete traceability — You know exactly where your invoice stands
• B2B preparation — In 2026, electronic invoicing between businesses also becomes mandatory

FAQ

Can I still send paper invoices to the public sector?

No. Since 2024, paper invoices and PDFs by email are no longer accepted for public procurement.

How much does sending a B2G invoice via PEPPOL cost?

At DIGIPOSA, invoice sending is included in your subscription from EUR 17.80/month.

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Ready to invoice the public sector? With Digiposapp, send your B2G invoices in just a few clicks.

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