Requesting a rent reduction: reference rate, calculation and procedure

The Federal Office for Housing publishes the rate every quarter, at the beginning of March, June, September and December. It is based on the average interest rate of all mortgages in Switzerland, rounded to a quarter of a percent. Since 2 September 2025 it stands at 1.25 percent; in September 2026 it was confirmed at that level.

• 1.25 percent: March 2020 to May 2023
• 1.50 percent: June to November 2023
• 1.75 percent: December 2023 to February 2025
• 1.50 percent: March to August 2025
• 1.25 percent: since September 2025

What matters for your claim is the rate your current rent is based on. It is stated in the lease or in the last rent adjustment; in cantons with a mandatory form, also on the initial-rent form.

Under Art. 13 of the VMWG ordinance, every cut of 0.25 percentage points entitles you to a rent reduction of 2.91 percent as long as the rate is below 5 percent. Several steps compound rather than add up. If your rent is based on 1.75 percent, two steps give a reduction of about 5.66 percent. On a net rent of 2,000 francs that is around 113 francs a month, more than 1,350 francs a year.

The landlord may offset: 40 percent of inflation since the rent was last set (Art. 16 VMWG) and general cost increases, in practice usually 0.5 to 1 percent a year. The offset has to be itemised. The landlord may also object that the rent is not excessive despite the cut; the yield then has to be disclosed.

The exact amount for your rent is shown by the reference rate calculator.

1. 1

   Check the rate in your lease

   If it is above 1.25 percent, you are in principle entitled to a reduction.

2. 2

   Request it in writing

   By registered mail to the landlord, citing Art. 270a CO, for the next termination date.

3. 3

   Wait 30 days

   The landlord has to respond within 30 days (Art. 270a para. 2 CO).

4. 4

   Go to the conciliation authority

   If the landlord refuses or does not answer, you again have 30 days, from receiving the answer or from the end of the 30 days, to apply to the conciliation authority. The procedure is free of charge.

• Your rent is already based on 1.25 percent, for example for leases from September 2025 or after a later adjustment.
• Index-linked rent (Art. 269b CO) or stepped rent (Art. 269c CO): during the term other rules apply and the reference rate plays no role.
• Cooperative flats with cost-based rent and subsidised flats follow their own rules.

If your landlord never passed on earlier cuts, you can claim all the steps from the rate the rent is based on. But the reduction is never retroactive: it applies from the next termination date after your request.

Then the landlord may raise the rent, but only with the official form, at least ten days before the start of the notice period and with a justification. You can contest the increase within 30 days at the conciliation authority. Check whether the landlord passed on earlier cuts; what was not reduced back then cannot be added now.