Introduction
An unpaid invoice can jeopardise your company's cash flow. In Belgium, many invoices between businesses are paid after the agreed term, and some are never paid.
This guide explains the complete recovery process, from the friendly reminder to the seizure.
Step 1: Friendly reminders
The first reminders
As soon as the payment term has passed, act quickly:
Day 1 (due date):
- Courteous reminder email
- Mention of the due date and the amount
Day 7:
- Reminder by telephone
- Ask for a payment commitment with a new date
Day 14:
- Firmer email
- Mention of the applicable default interest
Default interest
Between businesses, article 5 of the law of 2 August 2002 adds default interest to the unpaid amount. This interest runs automatically, without formal notice, from the day after the due date. The debtor escapes it by showing that it is not responsible for the delay. This rule results from the law of 14 August 2021, which amended the article.
The rate is set by law and published twice a year in the Belgian Official Gazette (Moniteur belge). It stands at 10.5% for the first and second half of 2026. Check it as at the date of your invoice: it changes every six months.
The flat-rate compensation
Article 6 of the same law, also amended in 2021, adds flat-rate compensation of 40 euros for recovery costs. It is due automatically, without formal notice, as soon as default interest is due. The amount is the same whatever the invoice. Reasonable recovery costs exceeding this flat rate may be claimed in addition, and must be proven.
Step 2: Formal notice
When to move to a formal notice?
If the friendly reminders remain without effect after 3 to 4 weeks, it is time to send a formal notice.
Content of the formal notice
The letter must be sent by registered post with acknowledgement of receipt and contain:
- A reminder of the debt (amount, date, invoice number)
- The default interest calculated
- The flat-rate compensation
- A payment deadline (generally 8 days)
- A statement that court proceedings will follow if payment is not made
What to expect from it
A formal notice from a lawyer sometimes prompts the debtor to settle amicably. The result is never automatic.
Step 3: Court proceedings
Option 1: Recovery of undisputed debts
The Judicial Code organises a procedure without a judge for undisputed money debts between businesses (articles 1394/20 to 1394/27). The creditor's lawyer entrusts it to a bailiff.
Conditions:
- Money debt that is certain and due, undisputed
- Creditor and debtor registered with the Crossroads Bank for Enterprises (BCE/KBO)
- Transaction concluded for the purposes of the business's activity
- No bankruptcy or judicial reorganisation in progress
Procedure:
- The bailiff serves a demand for payment, with the supporting documents and a reply form
- The debtor has one month to pay, request payment facilities or dispute
- If the debtor disputes, the procedure stops and you must go to court
- If the debtor does not react, the bailiff draws up a record of non-dispute
- This record, made enforceable, opens the way to seizure
Option 2: Summons before the court
For a disputed debt, the debtor must be summoned before the competent court. The procedure takes several months. The lawyer's fees are then priced per phase, on quote.
Option 3: Summary proceedings
In an emergency, the judge in summary proceedings may order provisional measures. The judge does not rule on the merits of the debt.
Step 4: Enforcement
Obtaining the enforceable title
Once the judgment is obtained, you have an enforceable title that allows you to compel payment.
Enforcement measures
Seizure of a bank account:
- The bailiff freezes the debtor's accounts
- The bailiff's costs are advanced by the creditor
Seizure of movable property:
- Seizure of equipment, vehicles, stock
- Sale at public auction
- Less effective if there are few assets
Garnishment of receivables:
- Seizure of the sums the debtor's own customers owe it
- Very effective for active businesses
Seizure of real property:
- For large debts
- Long and costly procedure
The case of bankruptcy
If the debtor is in financial difficulty, you must act quickly:
- File your claim with the trustee (curateur)
- Ranking of claims: preferential > unsecured
Conclusion
Debt recovery follows a logical order: friendly reminder, formal notice, court route, enforcement. At each step, the cost rises.
Tips to remember:
- Act quickly: the longer you wait, the more complicated recovery becomes
- Document everything: keep invoices, purchase orders, exchanges
- Calculate the return: sometimes, the cost of the procedure exceeds the debt
- Use a lawyer for formal notices
Good to know: part of the costs can be claimed from the debtor, such as the flat-rate compensation of 40 euros. The debtor still has to be solvent: what you advance is not always recovered. The fees for chasing an unpaid invoice appear on the pricing page.
Invoice unpaid for more than 30 days?
I handle debt recovery between businesses. Book a scoping call to assess your case.
Translated from the French original published on 22 January 2026. The analysis concerns Belgian and European Union law. Read the French original.