Reference Rate at 1.25%: When You Can Ask for Lower Rent

The Swiss mortgage reference rate stays at 1.25%. The Federal Office for Housing (BWO) confirmed this on 1 September 2026, valid from 2 September 2026 (BWO, 1 September 2026). The rate has not moved since 2 September 2025.

If your rent is still based on a reference rate of 1.5% or higher, you can in principle ask for a lower rent: 2.91% of the net rent for a gap of 0.25 percentage points, more for larger gaps. Nothing happens automatically. You have to ask your landlord in writing, and the landlord may offset part of the claim with inflation and higher costs.

The reference rate in September 2026

The reference rate is the benchmark for rent changes linked to mortgage interest. It follows the volume-weighted average interest rate on Swiss mortgage loans and is rounded to the nearest quarter percent (Art. 12a VMWG). The BWO publishes it on the first working day of March, June, September and December. It applies from the following day (BWO fact sheet, 2022).

On the reference date of 30 June 2026, the average rate was 1.31%, the same as one quarter earlier. The reference rate stays at 1.25% until the average falls below 1.13% or rises above 1.37%. The next publication is planned for 1 December 2026 (BWO, 1 September 2026).

If your rent was last set while the rate was 1.25%, the current rate gives you no claim. If it is still based on 1.5% or more, a claim exists in principle (BWO, 2026).

What a drop of 0.25 points is worth

With reference rates below 5%, a rise of 0.25 percentage points allows a rent increase of at most 3%. When the rate falls, rents must be lowered accordingly, unless the savings are offset by cost increases (Art. 13 VMWG). For a fall of 0.25 points, the BWO puts the claim at 2.91% of the net rent (BWO, 2026). That is the 3% increase reversed: 1 divided by 1.03 leaves 97.09%.

Larger gaps do not simply add up. Two steps give 5.66%, not 5.82%, and three steps give 8.26% (mietrechtspraxis rate table, 2026).

Only the net rent changes. Heating and service charges that are agreed separately are not affected (BWO, 2026).

What your landlord may set against it

Your landlord can accept the request, refuse it, or reduce it by offsetting other factors. If the landlord refuses or offsets, they must explain why (BWO, 2026). Two factors come up most often:

• Inflation: the rent may follow at most 40% of the rise in the Swiss consumer price index (Art. 16 VMWG).
• Cost increases: higher maintenance and operating costs can also justify a smaller reduction (Art. 269a CO).

So the reduction can be smaller than in the table above, or there may be none at all. It depends on when your rent was last set and on the figures your landlord can show.

Some leases do not follow the reference rate. These include indexed rents, staggered rents and turnover-based rents for business premises. Subsidised flats often have special rules. Rents for luxury flats and single-family houses with six or more living rooms (kitchen not counted) can be agreed freely (BWO, 2026).

Step by step: how to ask for a lower rent

1. Find your base rate. Look in your lease or in the last notice of a rent adjustment. If the rent was later adjusted to a new reference rate and you did not challenge it, the newer rate counts (BWO, 2026).
2. Compare it with 1.25%. At 1.5% or more, and with a rent that is neither indexed nor staggered, you have a claim in principle.
3. Check your termination dates. The reduction applies from the next possible termination date (Art. 270a CO). For flats, the notice period is at least three months (Art. 266c CO). Make sure your letter reaches the landlord before the notice period for that date starts.
4. Write to your landlord. The request must be in writing, and the BWO recommends a registered letter. State your base rate, the current rate of 1.25%, the percentage you ask for and the date it should apply from.
5. Allow 30 days for an answer. The landlord must reply within 30 days (Art. 270a CO).
6. Go to the conciliation authority if needed. If the landlord refuses, agrees only in part or misses the deadline, you have 30 days to go to your cantonal conciliation authority. If an answer arrives early, count the 30 days from that answer to be safe. Without any answer, the deadline ends at the latest 60 days after your request. Miss it, and you have to start again with a new request (BWO, 2026).

Example: your lease allows termination at the end of December with three months' notice. The notice period for 31 December 2026 starts on 1 October 2026, so your letter should arrive by 30 September 2026. The lower rent would then apply from 1 January 2027.

Where to get help with your own case

This guide explains the general rules. Your own claim depends on your lease, your last rent adjustment and the practice in your canton. Check your contract first. Then contact the conciliation authority in your canton: in tenancy matters, it also gives legal information (Art. 201 CPC). The BWO lists the addresses (BWO, conciliation procedure).

You can also turn to a tenants' association (Mieterinnen- und Mieterverband, ASLOCA in French-speaking Switzerland, ASI in Ticino), a homeowners' association or a lawyer. The BWO page on the reference rate also links to several online rent calculators.

Where Eini fits

A lower net rent changes your monthly budget, and it changes how your home compares with other places. The Housing module in Eini compares places by the full monthly picture: rent, taxes, health premium and commute. Two of our posts cover the next questions: cheaper rent or a shorter commute and what it costs to move canton. Housing is part of Eini Premium, which costs CHF 3 a week or CHF 90 a year.