How does statutory interest work?
Which interest applies depends on who your customer is and not on what you sell. A commercial agreement exists between businesses, or between a business and a public authority; everything outside that falls under ordinary statutory interest.
It is set differently from commercial interest. That follows automatically from the refinancing rate of the European Central Bank plus eight percentage points, and so changes by itself every half-year. Ordinary statutory interest only changes when the legislator takes a decision, and can therefore stand still for years.
For a sole proprietorship (eenmanszaak) that supplies both, that means two percentages in the same list of debtors. The type of customer determines which percentage applies, so you must record it per customer and not estimate it per invoice.
Where is statutory interest in the law?
These legal sources come from the specialist dossiers that were reviewed on 24 August 2026. Mind the difference that becomes large in a dispute: a statutory article next to a value is where that value is found, not a justification for how it applies to your situation.
- Article 6:119 of the Dutch Civil Code (BW)ordinary statutory interest; 4 percent as of 1 January 2026, by decision of 10 December 2025 (Staatsblad 2025, 438, the Dutch Bulletin of Acts and Decrees)
- Article 6:119a of the Dutch Civil Code (BW)commercial interest, which only applies to a commercial agreement
The links go to the statutory text on wetten.overheid.nl, in the version that applied on 24 September 2026.
What does basestep do with statutory interest?
Calculating with interest is not in yet. What is fixed for when it arrives: two series side by side, with the customer type as the switch. Knowing only one type of interest is worse here than knowing none, because then you systematically charge too much to half your customers.
All calculations, explanations and signals in basestep are calculation support and instruction, not tax or legal advice. Amounts are estimates based on your own input; the Dutch tax authority (Belastingdienst) sets the assessment.
Where does it go wrong with statutory interest?
The two mistakes you run into most often in practice with this term, and what they cost you.
One percentage for everyone
Charging a private customer commercial interest is more than a calculation error: you ask for money you have no right to, and that undermines the rest of your reminder.
Calculating the percentage yourself
With commercial interest you can, with this one you cannot. It is set by decision, so you look it up and do not calculate it.
Further reading
Three places this term is tied to, inside this glossary and beyond.