Challenging a rent increase in Switzerland – how to check it

Updated 25.09.2026 · Current reference rate 1.25 %

A Swiss rent increase must be notified on the form approved by the canton, give reasons and arrive at least ten days before the notice period begins – otherwise it is void (Art. 269d CO). If it is formally correct, you can challenge it as abusive at the conciliation authority within 30 days (Art. 270b CO). The procedure is free.

Step 1: Is the increase formally valid?

A landlord may raise the rent for the next possible termination date. Art. 269d CO sets strict formal rules. The increase must

• be notified on a form approved by the canton,
• give reasons, and
• reach you at least ten days before the notice period begins. With three months' notice to 31 March, the notice period starts on 1 January, so the form must arrive by 21 December.

The increase is void if the official form is missing, if no reasons are given, or if the landlord threatens or gives notice of termination with it (Art. 269d para. 2 CO). A void increase has no effect, whether or not you challenge it. An increase that arrives too late is not void, but as a rule only takes effect at the following termination date.

The form must show the old and new rent, the date from which it applies and the reasons, with amounts for each reason; it must also explain how to challenge the increase and name the conciliation authority (Art. 19 VMWG). A vague phrase such as "adjustment to market conditions" alone is not enough. For cost increases or value-adding investments you may ask for the figures (Art. 20 VMWG).

The same rules apply when the landlord changes the lease in some other way to your disadvantage – for example cutting services or introducing new service charges (Art. 269d para. 3 CO). See checking your service charge statement.

The deadlines at a glance

1. 10 days before the notice periodThe form must arrive

   For a termination date of 31 March with three months' notice: by 21 December.

2. Day 0You receive the increase

   Check the form, the reasons and the rate your rent is based on.

3. Within 30 daysChallenge at the conciliation authority

   After 30 days a formally valid increase becomes binding.

4. Usually a few weeks laterConciliation hearing

   Free of court costs; you keep paying the old rent in the meantime.

5. OutcomeSettlement, proposed decision or authorisation to proceed

   Often the increase is reduced or dropped – sometimes the rent even falls.

Step 2: Are the reasons justified?

A formally valid increase can still be abusive (Art. 269 and 269a CO). Common reasons and what to check:

More on each objection: landlord objections explained.

Step 3: Which rate is your rent based on?

This is where many increases fail. The check starts from the last binding rent basis – your lease, the last rent adjustment or a settlement. If the reference rate has fallen since then and the landlord never passed on the reduction, your rent is still based on the old, higher rate. The landlord must take earlier rate changes into account (Art. 13 para. 4 VMWG).

Example: your rent was set when the rate was 1.75 % and was never reduced. The rate then fell to 1.25 % and later rises to 1.50 %. Compared with your rent basis, the rate is still 0.25 point lower. A reference-rate increase is therefore not justified – on the contrary, you may still be entitled to a reduction. According to the Swiss tenants' association, challenging the increase is the last chance to correct reductions that were not passed on.

If the landlord reserved part of an earlier adjustment, the reservation must be stated in francs or percent (Art. 18 VMWG). Check the last adjustment notice for it.

You can raise a reduction claim together with the challenge; the prior written request to the landlord is then not needed (Art. 270a para. 3 CO). Our calculator shows what your rent would be on today's rate.

How to challenge

1. Within 30 days of receiving the increase, file with the conciliation authority for tenancy matters where the flat is located (Art. 270b CO). A short written application is enough; many offices have forms online. The offices are listed on our canton pages.
2. Attach the lease, the increase form, the last rent adjustment and your calculation.
3. The procedure is free of court costs (Art. 113 para. 2 lit. c Code of Civil Procedure). The hearing is informal; most cases end in a settlement. The course of the hearing is described in what to do when the landlord refuses.

If you miss the 30 days, a formally valid increase becomes binding. You can then only request a reduction later if the calculation basis changes again.

Rent and protection during the procedure

While the conciliation procedure runs without an agreement, the existing lease continues unchanged (Art. 270e CO): you keep paying the old rent, in full and on time. Paying less than the old rent can lead to arrears.

A termination because you assert your rights in good faith can be challenged (Art. 271a para. 1 lit. a CO). The protection also covers the procedure and generally the three years after it if the landlord largely loses or settles with you (Art. 271a para. 1 lit. d and e CO). Exceptions exist, for example urgent personal need or rent arrears.

Frequently asked questions

Sources

• Swiss Code of Obligations, Art. 269d, 270b, 270e and 271a CO (SR 220)
• Ordinance on the Lease of Residential and Commercial Premises, Art. 13, 14, 16, 18–20 VMWG (SR 221.213.11)
• Swiss Tenants' Association: rent increase
• Federal Housing Office: mortgage reference rate

Related guides

• Inflation, cost increases and more: checking your landlord's objectionsYour landlord rejects a rent cut citing inflation, costs or yield? How to check each objection under Swiss law, with the legal limits that apply.
• Landlord refuses your rent reduction – what to do nextRefused, partly accepted or no reply: within 30 days you can apply to the conciliation authority – free of charge and with protection from eviction.
• Checking your service charge statement – how to spot errorsWhich service charges a Swiss landlord may bill, what is excluded, and how to inspect receipts and object to errors. With a line-by-line checklist.
• Rent reduction request (Herabsetzungsbegehren): template & sampleSample letter for a Swiss rent reduction request under Art. 270a CO: content, deadline, registered mail and what happens after the landlord replies.

This guide explains the general legal position under Swiss tenancy law. It is not legal advice for your individual case. For disputes, contact your cantonal conciliation authority or a tenants' association.