If you run a business in the Netherlands and deal with overdue invoices, you need to understand incassokosten — the collection fees you can add to unpaid debts. Dutch law regulates exactly how much you can charge, when you can charge it, and what steps you must take first.
This guide covers everything: the WIK regulation, the fee schedule, the differences between B2B and B2C collection, and how to automate the entire process.
What Are Incassokosten?
Incassokosten (literally "collection costs") are fees that a creditor can charge to a debtor to cover the expenses of collecting an overdue payment. In the Netherlands, these fees are regulated by two pieces of legislation:
Wet Incassokosten (WIK) — The law that establishes the framework for collection fees. It defines when fees can be charged and sets the rules for the mandatory 14-day payment notice.
Besluit vergoeding voor buitengerechtelijke incassokosten (BIK) — The decree that specifies the exact fee schedule, including the tiered percentages and minimum/maximum amounts.
Together, these regulations ensure that collection fees are proportional to the debt and that debtors receive fair warning before fees are applied. The system protects both creditors (who deserve compensation for collection costs) and debtors (who should not face disproportionate penalties).
The WIK Fee Schedule: How Much Can You Charge?
The Dutch collection fee system uses a tiered structure. The percentage decreases as the outstanding amount increases, ensuring that fees remain proportional.
| Outstanding Amount | Percentage | Maximum Fee in Bracket |
|---|---|---|
| First €2,500 | 15% | €375.00 |
| €2,500 – €5,000 | 10% | €250.00 |
| €5,000 – €10,000 | 5% | €250.00 |
| €10,000 – €200,000 | 1% | €1,900.00 |
| Over €200,000 | 0.5% | Varies |
Minimum fee: €40 (even if the calculated amount is lower) Maximum fee: €6,775 (even if the calculated amount is higher)
- €1,000 × 15% = €150.00
- Total incassokosten: €150.00
- First €2,500 × 15% = €375.00
- Next €2,500 × 10% = €250.00
- Total incassokosten: €625.00
- First €2,500 × 15% = €375.00
- Next €2,500 × 10% = €250.00
- Next €5,000 × 5% = €250.00
- Next €15,000 × 1% = €150.00
- Total incassokosten: €1,025.00
- €100 × 15% = €15.00
- But minimum is €40, so: €40.00
Use our free incassokosten calculator to calculate the exact fees for any invoice amount.
The 14-Day Aanmaning: A Mandatory Step
Before you can charge incassokosten, Dutch law requires you to send a formal payment notice — the WIK-brief or aanmaning — giving the debtor 14 days to pay without additional costs.
The 14-day notice is not just a reminder. It must meet specific legal requirements to be valid:
The outstanding amount — State the exact amount owed, including the invoice number and original due date.
The 14-day deadline — Explicitly state that the debtor has 14 days from receipt of the letter to pay. The 14-day period starts when the letter is delivered, not when it is sent.
The incassokosten amount — State the exact collection fees that will be charged if payment is not received within 14 days. This amount must be calculated according to the WIK/BIK schedule.
Payment instructions — Include clear instructions on how to pay — bank account number, payment link, or other payment methods.
For consumer debts (B2C), sending the 14-day aanmaning is a strict legal requirement. If you skip this step or do not meet the content requirements, you cannot legally charge incassokosten — even if the debt is legitimate and overdue.
The aanmaning should be sent by letter (physical mail), not just email. While there is no explicit legal requirement for postal delivery, courts have ruled that email alone may not be sufficient proof that the debtor received the notice.
For business-to-business debts, the 14-day aanmaning is not strictly required by the WIK — the law primarily targets consumer protection. However, sending a formal notice is still best practice for several reasons:
It demonstrates reasonableness in case of a dispute. It gives the debtor a clear opportunity to pay before fees are added. And it creates a documented paper trail that strengthens your position if legal action becomes necessary.
B2B vs B2C: Key Differences
Understanding the distinction between business and consumer debts is critical for applying the correct collection fee rules.
For consumer debts, the WIK fee schedule is the legal maximum. You cannot charge more than the calculated amount, regardless of your actual collection costs. The 14-day aanmaning is mandatory. The notice must be sent before fees are applied. Courts will not enforce collection fees that exceed the WIK schedule or were charged without proper notice.
Consumers also benefit from additional protections. If a consumer disputes the debt, collection activities must pause until the dispute is resolved. And if the consumer demonstrates financial hardship, courts may reduce or waive collection fees entirely.
For business debts, the situation is more flexible. The WIK fee schedule is not a legal maximum for B2B transactions — it is commonly used as a reference, but businesses can agree on different terms in their contracts.
The EU Late Payment Directive (implemented in Dutch law as Article 6:96 BW) establishes a minimum of €40 in fixed recovery costs for B2B transactions. This applies automatically — no aanmaning is required for this minimum amount.
Beyond the €40 minimum, you can charge reasonable collection costs that you actually incurred. In practice, most B2B businesses use the WIK schedule as a guideline because it provides a defensible, standardized framework.
Tip: Include collection fee terms in your B2B contracts and general terms (algemene voorwaarden). This makes the fees contractually agreed upon, removing any ambiguity about what you can charge.
How to Automate Collection Fee Calculation
Manually calculating incassokosten for every overdue invoice is tedious and error-prone. The tiered system means you need to track which bracket applies and handle the minimum/maximum correctly.
Modern invoicing software with built-in debt collection automates the entire process:
Automatic calculation — When an invoice reaches the collection fee stage, the software calculates the exact incassokosten based on the WIK schedule. No spreadsheets, no manual math, no errors.
14-day aanmaning generation — The system generates a WIK-compliant payment notice with all required information, including the calculated fee amount. It can send this via email, SMS, or postal mail through Pingen.
Automatic fee application — After the 14-day period expires without payment, collection fees are automatically added to the outstanding balance. The client sees the breakdown in their customer portal.
Escalation pipeline — The software manages the entire collection timeline, from friendly reminders through formal notices to collection fee application and final warnings, all without manual intervention.
Payment plan support — If the debtor cannot pay the full amount (including fees) at once, the system supports splitting the debt into monthly installments that are billed automatically.
Common Mistakes to Avoid
For B2C debts, this invalidates your right to incassokosten entirely. For B2B debts, it weakens your legal position if the debtor disputes the charges. Always send a proper 14-day notice, even for B2B transactions.
Incassokosten are calculated on the original outstanding amount, not on the total including interest or previously added fees. Do not compound collection fees on top of collection fees.
The WIK schedule is mandatory for B2C debts but only a reference for B2B. If your B2B contract specifies different collection fee terms, use those terms — not the WIK schedule.
The 14-day notice must state the exact amount of incassokosten that will be charged. A vague statement like "collection fees may apply" is not sufficient. Calculate the amount and include it explicitly.
Getting Started
Stop calculating incassokosten manually. PayRequest's debt collection feature handles the entire process — from generating WIK-compliant aanmaningen to calculating fees, applying them automatically, and offering payment plans through the customer portal.
Calculate your collection fees now with our free incassokosten calculator, or start automating your debt collection at €20/month with all features included.