B2B Late Payment Interest and the €40 Flat Recovery Fee in Belgium: 2002 Act Guide

Key Takeaway: In Belgium, the Act of 2 August 2002 protects businesses and freelancers against commercial late payments. On the day immediately following the due date of an unpaid B2B invoice, statutory late-payment interest (set semi-annually by FPS Finance) and a statutory flat compensation of €40 for recovery costs apply automatically by operation of law, without requiring any prior formal notice. In B2C, these automatic penalties are strictly prohibited under Book XIX of the Belgian Code of Economic Law.

Waiting for payment on completed work strains your business cash flow. When corporate or business clients let an invoice slip past its payment term, freelancers and small business owners often hesitate to charge late fees out of fear of damaging customer relationships.

However, Belgian law provides a clear, dissuasive framework: the Act of 2 August 2002 on combating late payment in commercial transactions (transposing European Directive 2011/7/EU).

This legislation grants creditors robust automatic protections: statutory default interest and a mandatory €40 recovery fee that accrue on the very first day of delay without the need to serve a formal notice of default.

Here is how to calculate these penalties, apply them in your follow-ups, and avoid legal traps with private consumers.

1. The 3 Core Rules of the Belgian 2002 Late Payment Act

The Act of 2 August 2002 applies exclusively to commercial transactions between businesses (B2B) or between businesses and public authorities. It establishes three fundamental statutory principles:

1. Standard statutory payment term of 30 days: unless otherwise agreed in writing, B2B invoices are legally due within 30 calendar days of invoice receipt or delivery of goods/services. Parties can negotiate longer terms, but payment deadlines cannot exceed 60 calendar days unless explicitly agreed and not grossly unfair to the creditor.
2. Immediate and automatic interest accrual: from the day after the contractual due date (or on day 31 if no deadline was set), default interest starts running by operation of law. You do not need to issue a reminder letter or a formal notice to activate this interest liability.
3. Statutory flat compensation of €40: in addition to accrued daily interest, the creditor is automatically entitled to a flat fee of €40 intended to cover internal administrative debt-collection overhead.

Warning: This law never applies when dealing with private individual consumers (B2C). Charging the €40 fee or applying automatic interest without a mandatory 14-day free reminder to an individual consumer is strictly prohibited in Belgium under Book XIX of the Code of Economic Law.

2. What Is the Belgian Statutory Rate and How to Calculate It?

The statutory interest rate under the 2002 Act is not static: it is updated semi-annually by the Belgian Federal Public Service (FPS) Finance and published in the Belgian Official Gazette (Moniteur belge).

The rate equals the European Central Bank's main refinancing rate plus 8 percentage points. In recent years, with higher ECB base rates, this commercial statutory rate has hovered between 10.5% and 12.5% per year.

Mathematical Formula for Statutory Default Interest

To calculate interest on an overdue commercial invoice, use the standard statutory formula:

Interest amount = (Total gross invoice amount incl. VAT x Annual statutory rate x Number of days overdue) / 365

Concrete Calculation Example

Consider a service invoice of €3,500 gross (incl. VAT), due on 15 January 2026. On 1 March 2026, the invoice remains unpaid (45 days overdue). The applicable statutory rate is 12.5% per year.

1. Accrued statutory default interest:
   (€3,500 x 0.125 x 45) / 365 = €53.84
2. Statutory flat recovery compensation:
   Article 6 of the Act of 2 August 2002 = €40.00
3. Total claim payable by debtor:
   €3,500 + €53.84 + €40.00 = €3,593.84

This total is legally payable immediately. If your actual recovery expenses (such as legal counsel or bailiff costs) exceed €40, Article 6 explicitly allows you to claim additional reasonable compensation to cover the difference.

3. Comparison of Belgian Payment Delay Regimes: B2B vs B2C

Rules governing overdue invoices differ fundamentally depending on whether your customer is a business or a private consumer:

To structure your contractual documents correctly from quote to invoice, see our detailed guide on B2B vs B2C quotes: mandatory mentions and terms.

4. Late Payment Fee Breakdown Template for B2B Reminders

When sending a second reminder letter for an unpaid invoice or a formal demand letter to a business client, insert this standard breakdown block:

Outstanding Debt Breakdown as of [Current Date]:

• Principal invoice amount No. [FAC-2026-XXXX] dated [Issue Date]: €[Amount]
• Original due date: [Due Date] ([X] days overdue)
• Statutory default interest (Belgian Act of 2 August 2002, rate of [X]% p.a.): €[Calculated Amount]
• Statutory recovery compensation (Article 6 of the Act of 2 August 2002): €40.00
  Total amount payable immediately: €[Total Claim]

Legal statutory note: In accordance with the Belgian Act of 2 August 2002 on combating late payment in commercial transactions, these fees and interest charges accrue by operation of law without prior formal notice.

FAQ: Frequently Asked Questions About Belgian B2B Late Payment

Is the €40 fixed compensation subject to VAT?

Must the €40 fee be stated in your terms and conditions to be claimed?

What happens if the customer only pays the principal invoice balance?

How HeyDevis Automates Late Fees and Chasing in Belgium

Manually counting days overdue and tracking semi-annual interest rate fluctuations wastes valuable administrative hours.

With HeyDevis, managing late payments is effortless:

• Overdue detection: your dashboard alerts you immediately when an invoice passes its maturity date.
• Automated penalty calculations: HeyDevis applies official Belgian statutory rates, computes interest pro rata to the exact day, and adds the statutory €40 fee in one click.
• Scheduled compliant reminders: send professional, compliant reminders containing the legal breakdown and required Belgian statutory notices.