How to request a rent reduction after the reference interest rate falls

In Switzerland, most residential rents are linked to the reference interest rate. This rate is published every quarter by the Federal Office for Housing (OFL). When it falls, the landlord does not have to reduce the rent of their own accord: it is up to the tenant to ask. Art. 270a of the Swiss Code of Obligations (CO) allows you to demand a reduction for the next termination date when the basis for calculating the rent has changed significantly, in particular because of a fall in costs. As the rate changes over time, always check the latest OFL publication before you act.

The first step is to identify the rate on which your current rent is based. It is usually shown in the lease or in the last notice of a rent increase or reduction. Then compare it with the reference interest rate currently in force. If it is lower, you are probably entitled to a reduction.

For the calculation, the Ordinance on the Lease of Residential and Commercial Premises (OBLF) sets a simple rule. When the reference interest rate is 5% or lower, each increase of 0.25 points justifies a 3% rise (art. 13 OBLF), which conversely corresponds to a reduction of about 2.91% for each 0.25-point fall. A fall of 0.5 points therefore lets you ask for a reduction of about 5.74%, because the percentages are calculated one after the other and are not simply added together.

However, the landlord can offset this reduction with other factors. In particular, they can claim inflation, up to 40% of the rise in the Swiss consumer price index since the rent was last set (art. 16 OBLF), as well as increased maintenance and operating costs. These offsets must be justified: you are entitled to ask for a detailed calculation.

Your request must be made in writing, ideally by registered post. State the address of the property, the current net rent, the reference interest rate on which it is based, the new rate published by the OFL, the reduced rent you are asking for and the effective date, that is, the next termination date, respecting the notice period set out in the lease. The landlord has 30 days to reply (art. 270a para. 2 CO). If they refuse, grant only a partial reduction or do not reply, you can refer the matter to the conciliation authority within the following 30 days. This procedure is free of charge (art. 113 para. 2 let. c CPC), and the landlord cannot give you notice for this reason, as a termination given because the tenant asserts their rights can be annulled (art. 271a CO).

If you have just moved in, there is another option: challenging the initial rent (art. 270 CO). You can refer the matter to the conciliation authority within 30 days of taking possession of the property if you were forced to sign the lease because of your personal or family situation or a housing shortage, or if the rent was significantly increased compared with the previous tenant's rent. In cantons that require it, the landlord must use an official form stating the previous rent.

SwissDoc generates the rent reduction request addressed to your landlord, as well as the application challenging the initial rent. Your first three documents are free, no credit card required.