Commercial space lease: don't forget to apply indexation

No, the annual indexation of the rent for commercial premises is not an automatic process that you can simply forget – but if you do forget it as a landlord, you usually do not immediately lose your right to it. Almost every lease agreement contains an indexation clause that adjusts the rent annually, often based on the CBS CPI index. If your contract contains an ROZ-style clause that makes the indexed rent due and payable without notice, you can in principle collect arrears of indexation going back up to five years (the limitation period of Article 3:308 of the Dutch Civil Code). Without such a clause, or after remaining inactive for too long, you run the risk of losing your entitlements. The turn of the year is the perfect time to review your lease agreement.

What is rent indexation?

Indexation means that the rent is periodically adjusted to reflect the rise in the cost of living, so that the real value of the rent remains stable. In most commercial lease agreements, this is done annually based on the Consumer Price Index (CPI) published by Statistics Netherlands (CBS). The rent then increases in line with inflation.

The indexation clause stipulates the date on which the rent is adjusted, which index serves as a guideline, and how the calculation is performed. It is therefore a fixed, recurring obligation agreed upon in the contract – not a one-off negotiation.

This is how the calculation works (calculation example)

The most commonly used formula is: new rent = old rent × (new index / old index). Suppose the rent is €2,000 per month and the relevant CPI index has risen by 4% in a year. Then the new rent becomes €2,000 × 1.04 = €2,080 per month. The exact index figures and reference month are stated in your contract; always consult the current CBS figures and the wording of your specific clause, as these determine which month and which series (for example, “all households”) you must use.

Indexation for commercial premises: considerable contractual freedom

For the rental of residential property, the legislator has legally framed indexation. When renting commercial property, however, you have considerably more freedom to make your own arrangements. For instance, you can agree that:

• the rent is increased annually by a fixed percentage ;
• the rent follows the CBS CPI index ;
• another index or measure is used as a guideline.

Which variant fits best depends on your position and the type of property. When we at MKB Juristen draft a lease agreement for commercial premises , we always determine which indexation clause best suits your situation.

Indexation in the ROZ model rental agreements

In practice, many landlords use the model lease agreement of the Council for Real Estate (ROZ). The ROZ model assumes that the annual rent indexation is calculated based on the index figure of the year in which the rent was last changed.

In the ROZ model, you manually enter when the rent is adjusted and the date effective from which this takes place for the first time. This often states January 1st, making the turn of the year the natural moment to dust off the lease agreement and implement the adjustment.

Please note that the more recent ROZ models (such as Retail Space 2022 and Office Space 2015) offer a selection menu for indexation: the CPI is no longer mandatorily the sole measure. Therefore, always check which version and which variant has been selected in your contract.

What if you forget to apply the indexation?

This is precisely where the wording of the clause makes the difference. The ROZ model contains a provision making the indexed rent due and payable even without separate notification to the tenant. At MKB Juristen, we also ensure that such a clause is included in the lease agreement, as it has far-reaching consequences.

Without such a clause

If the landlord fails to apply indexation and there is no clause making the increase automatically due and payable, this may constitute improper contract management. The landlord then runs a greater risk of losing their claims to the forgotten indexation.

With such a clause

If the clause is included, the situation is different. Dutch case law has repeatedly ruled that a landlord does not automatically lose their claims to forgotten indexations with such a clause. A forgotten increase remains, in principle, enforceable, even if it has not been communicated for years.

Important nuance: claims for payment of (arrears) rent – ​​including forgotten indexations – generally expire five years after they become due. This follows from Article 3:308 of the Dutch Civil Code, which applies to everything that must be paid annually or over a shorter period, such as rent. Consequently, a landlord can generally not collect such a claim indefinitely far into the past. The annual indexation itself may be applied from the original start date; only the actual collection of the outstanding amount is limited by the statute of limitations.

Processing legal proceedings: doing nothing can cost you dearly

In addition to the statute of limitations, estoppel also plays a role. If a landlord fails to apply indexation for years and the tenant was therefore entitled to assume that the rent would no longer be increased, invoking the right to collect the rent retroactively may, under certain circumstances, be contrary to reasonableness and fairness. However, in case law, a plea of ​​estoppel is only granted in exceptional circumstances: merely invoicing the old (non-indexed) rent for years is generally insufficient for this. Whether this applies depends heavily on the facts: the wording of the clause, the conduct of the parties, and the duration of the inaction. A clause that makes the increase automatically due and payable makes a successful plea of ​​estoppel by the tenant more difficult, but does not completely rule it out.

Step-by-step plan: collect forgotten indexation

Have you discovered that, as a landlord, you have not applied indexation for years? Then follow these steps before sending an additional assessment:

1. Read your clause. Does your contract contain a provision similar to the ROZ that makes the indexed rent due and payable even without notice?
2. Determine the period. How far back can you go, given the five-year limitation period (Article 3:308 of the Dutch Civil Code)?
3. Calculate the shortfall. Apply the correct CBS index figures per year and correctly stack the increases.
4. Test regarding estoppel. Was the tenant entitled to rely on the fact that you definitively waived the indexation?
5. Communicate in writing and with supporting evidence. Send a clear calculation and a reasonable payment term.

Are you unsure about any of these steps? Then have your contract reviewed first – an incorrect additional assessment can lead to unnecessary disputes.

The importance of good clauses and sound contract management

A correctly formulated indexation clause can make a world of difference, even if you, as the landlord, have been negligent yourself. However, it is not a miracle cure. Sound contract management, with attention to terms and expiration dates, remains crucial. Specifically, it helps to:

• to put the indexation date (often January 1) in your calendar;
• to look up the current CPI index figure at Statistics Netherlands annually;
• to record the calculation and the new rent in writing, even if the clause does not require notification;
• to have your clause checked if you are in doubt whether forgotten increases are still enforceable.

Is the tenant behind in the payment of a correctly applied indexation? In that case, a timely collection process offer a solution.

Frequently asked questions about indexation of commercial space rent

Am I allowed to index the rent of commercial premises annually?

Yes, if that has been agreed in the lease agreement. For commercial premises, there is a great deal of contractual freedom: you can agree on a fixed increase, the CPI index, or another benchmark. Without an indexation clause in the contract, there is, in principle, no right to annual indexation.

On which index is the rent usually based?

In most contracts, including many ROZ models, the CBS Consumer Price Index (CPI) is used. In newer ROZ models, the CPI is no longer mandatorily the sole measure. The exact index figure and the calculation are stated in the index clause of your contract.

I forgot the indexation last year. Can I still collect it?

Often yes, especially if your contract contains an ROZ-style clause that makes the indexed rent due and payable without notice. Keep in mind that claims for payment generally become time-barred after five years and that estoppel may play a role. Have your situation assessed before sending a supplementary assessment.

How far back can I claim forgotten indexations?

The general rule is that claims for payment of rent arrears become time-barred after five years (Article 3:308 of the Dutch Civil Code). While the indexation itself may be passed on from the original start date, the actual collection of the outstanding amount is limited by this limitation period.

Do I have to inform the tenant about the rent increase?

That depends on your clause. In the ROZ models, the indexed rent is due and payable even without separate notification. Nevertheless, it is advisable to communicate the increase in writing and in a timely manner to avoid misunderstandings and disputes.

How do I calculate the indexed rent?

Usually, you multiply the applicable rent by the new index figure divided by the old index figure. For example, with a 4% increase, this means a rent of €2,000 going to €2,080. Check your contract to see which reference month and CBS series apply.

Have a rental agreement checked or drafted?

Are you unsure if your indexation clause is watertight, or do you want to collect forgotten indexations without legal risk? Then have your lease agreement legally reviewed. Our legal experts assess whether your contract offers sufficient protection and help you draft binding agreements. Want to know more about your position as a landlord or tenant? View our page on tenancy law or schedule a no-obligation intake .