Is the increase valid? Check these points
- Official form. It came on the form approved by your canton (Art. 269d OR).
- Reasons. The form states clear reasons. Several reasons must each be shown as its own amount (Art. 19 VMWG).
- Timing. It reached you at least ten days before the notice period starts and takes effect on the next possible termination date (Art. 269d OR).
- No threat. It does not threaten or give notice (Art. 269d OR).
If one of points 1, 2 or 4 fails, the increase is void (Art. 269d OR). For increases already agreed in a staggered rent, written form is enough (Art. 269d OR).
Reasons the law accepts
| Reason | Rule |
|---|---|
| Higher reference interest rate | A rise of a quarter point allows, as a rule, at most 3% more rent while the rate is below 5% (Art. 13 VMWG) |
| Higher costs | For example fees, property taxes, insurance premiums, maintenance (Art. 12 VMWG) |
| Inflation | At most 40% of the rise in the consumer price index (Art. 16 VMWG) |
| Investments that add value | After the work is done and the receipts exist. Full overhauls count as a rule 50 to 70% as added value (Art. 14 VMWG) |
| Local level | Rent within what is customary in the place or neighbourhood (Art. 269a OR) |
The reference interest rate today
The mortgage reference rate is 1.25%. It has applied since 2 September 2025 (Federal Office for Housing, BWO, checked 9 November 2026). It is published every quarter (Art. 12a VMWG). When the rate falls, rents are to be lowered accordingly or the saving set off against cost increases (Art. 13 VMWG). You can ask the landlord for a reduction in writing. The landlord has 30 days to answer, and after that you have 30 days to go to the conciliation authority (Art. 270a OR).
Challenging an increase
Write to the conciliation authority within 30 days after the increase was communicated to you (Art. 270b OR).
How aptari helps
To judge an increase, it helps to know what comparable flats ask today. Median asking rents in the aptari feed on 9 November 2026: Zurich CHF 2,550, Bern CHF 1,924, Basel CHF 1,755, Switzerland CHF 1,860. Asking rents are the rents shown in listings, not official statistics and not proof of the local level in a legal dispute. If you decide to move, the Match Score shows how your income fits each rent.
This is general information, not legal advice.