How to Use Structured Communication on Belgian Invoices

What is structured communication?

In Belgium, a structured communication is a 12‑digit payment reference commonly displayed as +++XXX/XXXX/XXXXX+++. When the payer copies it correctly, banks and accounting tools can use the reference to propose a match with the corresponding invoice. It is a reconciliation aid, not a requirement introduced by the 2026 structured e‑invoicing obligation.

Why it matters for your business

• Automatic matching – Payments that contain the correct code are recognised by the bank and can be posted to the right invoice without manual searching.
• Error detection – The final digits are a check value that helps systems detect invalid references before matching.
• Improved cash‑flow visibility – When payments are matched automatically, you can see outstanding invoices in real time, which helps you follow up on late payments.

How the code is built

The 12‑digit code consists of two parts:

1. Base number (10 digits) – usually derived from the invoice number or a sequential reference assigned by your accounting system.
2. Check digits (2 digits) – calculated automatically to detect typing errors.

Many invoicing solutions can generate the reference. Test the result with your bank or accountant before enabling it on every invoice, especially if you derive the base number from an existing invoice sequence. The check value uses a modulo‑97 calculation, but users should not have to calculate it manually.

Placing the code on your invoice

Add the structured communication together with the other payment details, for example:

Please transfer the amount to IBAN BE13 7340 6707 8539
with reference +++026/0023/00148+++.

Best practice for layout

• Position the reference line prominently, directly under the IBAN and amount.
• Use a legible size and keep the separators expected by the payment workflow.
• If your software supports it, include a QR‑code that pre‑fills the IBAN, amount and reference when scanned with a banking app. The QR‑code should be placed on the same line or in a margin that does not interfere with the printed invoice layout.

Handling customers who do not use the code

Not every payer will include the structured communication, especially private individuals or foreign companies unfamiliar with the Belgian system. You can encourage correct usage by:

• Displaying the reference in a large, clear font.
• Adding a QR‑code for easy scanning.
• Stating in your payment terms that the reference is required for timely processing (e.g., “Please use the above reference; payments without it may be delayed”).

When a payment arrives without the code, you can still match it manually by:

1. Checking the amount against open invoices.
2. Using the payer’s name or customer number as a clue.
3. Recording the manual match in your accounting system and, if possible, sending a confirmation to the customer.

Practical checklist for implementing structured communication

• Software verification – Confirm that your invoicing or ERP system generates the 12‑digit code automatically.
• Template update – Insert a dedicated line for the reference next to the IBAN and amount in your invoice template.
• QR‑code activation – Enable QR‑code generation for payment details if your software offers it.
• Test run – Create a sample invoice, send it to a colleague, and verify that the reference appears correctly on the printed and PDF versions.
• Payment terms – Add a short clause requesting the use of the structured communication.
• Staff training – Brief accounting staff on how to identify payments without the code and the steps for manual matching.
• Monitoring – After launch, review the proportion of payments that include the code during the first month and adjust communication if needed.

Workflow for processing incoming payments

1. Bank statement import – Import the daily bank statement into your accounting software.
2. Automatic matching – Let the system match payments that contain a valid structured communication.
3. Exception list – Review the list of unmatched payments.
4. Manual investigation – Use amount, payer name, and invoice dates to locate the correct invoice.
5. Record the match – Mark the invoice as paid and add a note if the reference was missing.
6. Customer follow‑up – If mismatches are frequent, send a polite reminder explaining the importance of the reference.

Where to find official information

The structured communication is separate from the structured invoice itself. For the 2026 B2B invoice rules, consult the official Belgian e‑invoicing FAQ. Verify payment-reference configuration with your accountant, bank and software provider.