The Referenzzinssatz stays at 1.25 percent — do you have to lower the rent? Not automatically.

The mortgage reference rate (Referenzzinssatz) has stood at 1.25 percent since 2 September 2025 and remained unchanged in June 2026. Many landlords read this as an order: «Lower the rent now.» That is not correct. A reduction of the reference rate does not oblige you automatically — it gives your tenant a claim that he must first assert. And you may offset against it. This article shows when, how much and how you should respond.

What the Referenzzinssatz is — and what it is not

The Referenzzinssatz (mortgage reference rate) is the benchmark for rent adjustments during an ongoing tenancy. What counts is not the SNB policy rate, but the mortgage reference rate. It is based on the banks’ average mortgage interest rate and is rounded to the nearest quarter percentage point.

The body that lowers or raises the rate is the Federal Housing Office (Bundesamt für Wohnungswesen, BWO). The current level: 1.25 percent. If the average interest rate changes, the reference rate can move as well — the BWO publishes it periodically. The current level is available on the BWO’s website; we link there via our sources page.

The fallacy: «lowered» does not mean «automatically lower»

This is where practice parts ways with gut feeling. A reduction of the reference rate does not by itself lead to a lower rent. During the tenancy, the tenant may request a reduction of the rent as of the next possible termination date if the basis of calculation has changed substantially — above all in the case of a cost reduction such as the reference rate. He must submit this request in writing. You as the landlord must then respond within 30 days.

In concrete terms: as long as no request has been made, nobody lowers anything on their own. If one arrives, a deadline starts running — and a calculation begins, not an automatic mechanism.

How much — the order of magnitude

The permissible adjustment is not freely selectable, it follows fixed rates. Where the reference rate falls by 0.25 percentage points, the resulting claim to a reduction is in principle 2.91 percent of the net rent (Nettomietzins). That is the starting point — not the final result.

Because you may offset against it. Two items are central:

• Inflation compensation: The rent may be adjusted by at most 40 percent of the increase in the national consumer price index, calculated since the last rent setting.
• General cost increases: Increases in charges, insurance premiums and maintenance costs since the last rent setting also count.

The decisive words are «since the last rent setting» — only what has changed since then counts. And: only the net rent (Nettomietzins) is adjusted, not the separately agreed heating and ancillary costs (Nebenkosten under Art. 257a OR).

The strongest objection — and the answer to it

An informed owner rightly says: «If my contract is based on a higher reference rate, I owe the reduction anyway — whoever drags it out loses the conciliation case in the end.» That is correct. The only question is: which rate is your contract based on?

The five steps are shown in the graphic.

1. 1

   Contract basis

   Which reference rate is stated in the tenancy agreement or in the last adjustment?

2. 2

   Claim

   Is today's rate lower than the relevant one — and has no adjustment been made yet?

3. 3

   Timing

   The claim takes effect as of the next possible termination date after the request.

4. 4

   Offsetting

   Inflation and cost increases — only with evidence, only since the last rent setting.

5. 5

   Deadline

   Respond to a written reduction request within 30 days.

Legal provisions with sources on the sources page.

Important: the landlord can fend off a reduction request by demonstrating that he is not obtaining an excessive return from the rental property. The offsetting calculation is therefore not a trick but is provided for by law — it does, however, require supporting evidence.

The limits of this article

The rates are clearly regulated, their application in the individual case is not. Assessing inflation and cost increases depends on your specific figures and on the last rent setting; the practice of the conciliation authorities (Schlichtungsbehörden) varies from canton to canton. This article is not legal advice and not advice on an individual case. In the event of a dispute, the conciliation authority is competent; for the calculation, consult a specialist.

What to do now

Get out the tenancy agreement and look for the relevant reference rate. After that you will know whether a claim is on the table at all — and what you can offset against it. All figures and legal provisions mentioned here can be found with their source on our sources page.

You would rather not calculate rent adjustments yourself? Request a quote.

All figures and legal references in this article are disclosed and linked → Sources.