The CPI-Plus-Surcharge Clause Is the Biggest Refund Pot in Dutch Rentals — and Internationals Never Touch It

Most internationals I talk to signed their Dutch lease in a hurry. They arrived with a suitcase and a BSN appointment, the housing market was brutal, and the contract was in Dutch. They signed where the agent pointed.

Buried in that contract is usually a line about annual rent increases: CPI plus a fixed percentage. Three percent, sometimes five. It looks like boilerplate. It is not.

The Dutch Supreme Court drew a line in November 2024. CPI indexation on its own is fine. A surcharge up to 3% is, in principle, not unfair — provided it's foreseeable and serves a legitimate purpose. Above 3%, courts start asking harder questions. And in December 2025, the Amsterdam Court of Appeal found a 5% surcharge lacked sufficient transparency and materially distorted the balance against the tenant. It was struck out entirely — not trimmed to 3%, gone.

If your lease has a surcharge steeper than 3%, that ruling is about you.

Here's what most people miss: when a surcharge clause is found unfair, it's struck in full. Only the CPI portion survives. Courts are even required to review these clauses on their own initiative, whether or not the tenant raises the issue.

That means you can claim back the difference between what you actually paid and what you would have paid with CPI-only increases. The lookback runs up to five years.

The numbers aren't abstract. A tenant who overpaid €220 a month for 24 months is looking at €5,280. In Amsterdam, where rents are high and surcharges compound year after year, it climbs faster. DutchNews reported estimates of hundreds of thousands of eligible tenants and total refunds potentially in the hundreds of millions of euros.

And in April 2026, the Amsterdam Court of Appeal went further: even a 3% surcharge can be unfair if the landlord can't concretely justify it for that specific property. General references to rising costs don't cut it. The cumulative effect over several years counts.

Internationals are the most likely group to have signed a template lease from an agency, unchecked, in a language they don't fully read. They're also the least likely to ever challenge it.

Four reasons, and I've seen all of them.

Awareness. Most don't know the Huurcommissie exists, let alone that filing costs €25 and is refundable if you win. The process takes three to six months. If the Huurcommissie rules your way, the landlord has to refund within 30 days.

Transience. By the time an expat learns the rule exists, they're packing. Filing from another country against a Dutch landlord feels like a project nobody has time for.

Fear. Dutch law prohibits retaliatory eviction for filing a Huurcommissie complaint. That doesn't stop people worrying about a non-renewal or a bad reference in a market where finding the next place is already miserable.

And the lease itself. It's in Dutch. The clause is on page eleven. Nobody translates page eleven.

It's less intimidating than it sounds. You file with the Huurcommissie, pay €25, and wait. If the landlord refuses to comply with a favourable ruling, you escalate to the kantonrechter — the subdistrict court — where the fairness review is mandatory.

The catch is the paper trail. You need your lease, your rent increase letters, and a clear picture of what you paid versus what CPI-only would have been. Landlords and agencies are supposed to send annual increase notices; if yours arrived in Dutch and you ignored it, dig it out now.

The other catch is timing. The five-year window is generous but not infinite, and it moves with you. If you left the Netherlands two years ago and your old lease had a 5% surcharge, you may still have a claim. Most people in that position have already mentally closed the file.

This isn't a story about tenants being lazy. It's a story about a system designed around a tenant who knows the rules, speaks the language, and plans to stay.

The Huurcommissie route assumes you'll be here in three to six months. The five-year window assumes you'll keep your paperwork. The Dutch-language lease assumes you'll read it. Every assumption fails for the exact group paying the highest rents in Amsterdam, Rotterdam, Utrecht and Den Haag.

Landlords, meanwhile, are being told by their own lawyers to review their tenancy agreements and stop relying on outdated templates. The legal risk has shifted. Tenants just haven't caught up.

At House Hunter we watch over a thousand housing sites, and the listings we surface are the ones people sign fast. That speed is exactly why the clause gets missed. The lease is the last thing anyone reads carefully when they've finally found a place.

Find your lease. Search it for the words "indexering" or "CPI" or a percentage next to "huurverhoging." If there's a surcharge above 3%, you have a question worth asking. If it's exactly 3%, you still might — the April 2026 ruling means the landlord has to prove the surcharge was necessary for your specific property, not just cite the market.

Then find your increase letters. Add up what you paid versus CPI-only. That number is your claim.

And if you're an international who's already left: the window hasn't necessarily closed. The money sitting in an old Dutch lease doesn't disappear because you moved to Lisbon.

The rule exists. The court has drawn the line. The only thing standing between most internationals and a few thousand euros is a lease they never translated.