Amsterdam Court of Appeal: “Maximum 3% increase” may still be unfair

Since the Supreme Court’s preliminary ruling of November 29, 2024 (ECLI:NL:HR:2024:1780), the starting point for rent indexation clauses in deregulated residential housing has become clearer: a composite clause combining CPI indexation and a surcharge can be split, after which both components are assessed separately for unfairness. In practice, this provided many landlords with guidance, especially regarding a surcharge “up to a maximum of 3%”: after all, the Supreme Court ruled that such a surcharge can generally remain within acceptable limits.

The judgment of the Amsterdam Court of Appeal dated March 10, 2026, shows that the word “generally” is the real turning point. The court concluded that CPI indexation remains in effect, but that the maximum 3% surcharge clause is unfair and therefore voidable in this specific case. This shifts the debate: the question is no longer whether 3% is theoretically permissible, but when 3% is ultimately invalidated in practice.

A 3% surcharge is not automatically “safe”

The fact that a surcharge clause of up to 3% can be unfair is not new in itself (the Supreme Court explicitly left that possibility open), but the court of appeals demonstrates here exactly where the vulnerability lies. The crux of the matter is that the court rigorously assesses the surcharge clause against the European standard of Directive 93/13, placing significant emphasis on transparency and predictability for the tenant at the time the contract is concluded.

A 3% surcharge seems straightforward on paper. The court contrasts this with a reality that remains underexposed in many cases: the cumulative effect of an annual surcharge, on top of the CPI, in a lease agreement that often runs for a long period. The court illustrates this with a graph and a calculation example and subsequently concludes that it is not plausible that an averagely informed tenant could actually foresee those financial consequences at the outset. Precisely the ability to estimate the financial impact in advance is a recurring focal point in EU case law regarding price adjustment clauses.

Transparency, therefore, refers not only to understandable language, but also to the ability to fully grasp the economic implications over the term of the agreement. The notion that “the percentage is stated, so it’s transparent” clearly does not apply here.

No clear “valid reason” and yet a unilateral increase

The court also takes into account the indicative list in the Directive. A clause that authorizes the landlord to unilaterally amend a lease agreement without a valid reason being specified in the agreement quickly falls into the danger zone. In this case, a contributing factor was that the clause did not specify why and under what conditions the surcharge would be applied. This gives the landlord broad discretion, while the tenant has little basis for assessing whether the increase is justified.

In the same vein, the assessment is based on the scenario that the landlord always applies the maximum surcharge. It is not only about how the clause is “usually” used, but also about the risk that the clause, if fully utilized, could disrupt the balance of the agreement.

Terminating the lease as a theoretical solution is often not a realistic option

Another factor is the tenant’s (im)possibility of avoiding a rent increase by giving notice. The court emphasizes that, in a tight housing market, this option to terminate the lease is often not a realistic alternative. Consequently, a “safety valve” that might be considered in the abstract when evaluating rent adjustment clauses becomes less convincing in practice. On this point, the court thus follows the Supreme Court. The deviation from the Supreme Court lies solely in the final conclusion: whereas the Supreme Court ruled that a surcharge of up to 3% generally remains within acceptable limits, the court concludes that this is not the case here.

Disturbed balance: comparison with the legal framework

The Court of Appeal also examines whether the rent increase clause places the tenant in a legally less favorable position than under the statutory framework in effect at the time. Back then (in short), landlords had the option to reach an adjustment through a reasonable proposal and ultimately judicial review, in which personal circumstances and affordability, among other factors, could play a role. An automatic rent increase without that safeguard can then lead to higher outcomes than what would have been reasonable through the statutory route. This, too, contributes to the conclusion that the balance is significantly disrupted to the detriment of the tenant.

No “remedy” through a replacement clause

Finally, the court is clear on a point that is sometimes overestimated in practice: a contractual provision stating that a void provision will be replaced by “the closest alternative” does not help. If a clause is unfair under consumer law, the court may not modify or replace it. The deterrent effect of the Directive precludes this.

What does this mean in practice?

The most important lesson is that a surcharge clause is not “screened” solely on the basis of a percentage, and that a 3% surcharge is not automatically safe, according to the court. In concrete terms, this means that the landlord must be able to explain what the surcharge covers, why it may be necessary, and what the effect will be over time—in such a way that the tenant can foresee those consequences from the outset. This does not necessarily require a calculation example in the contract text, but the broader question is whether the tenant, as a normally informed and reasonably prudent consumer, was able to understand the financial consequences. In many standard clauses, this is not sufficiently the case.