Swiss tenancy law: What tenants in Zurich need to know

by MietenCheck Team • August 24, 2025 • Reading time ~18–25 min

Tenancy law isn’t magic — it’s precise. If you understand the core principles, you save money, nerves and time. This guide brings together the most important rules for Zurich: from contracts, deposits and utilities to defect rights, rent increases, the reference interest rate, protection against termination, subletting and mediation. It includes practical examples, checklists and trusted sources — clear, objective and actionable.

Contents

Basics & legal sources

  • Swiss Code of Obligations (CO), arts. 253 ff. — core rules for start of tenancy, defects, utilities, increases & termination.
  • Ordinance on the Tenancy and Lease of Residential and Business Premises (VMWG) — details like forms and cost allocation.
  • Canton/City of Zurich — official forms, conciliation authority, local practice & information sheets.
  • Guiding principle: abusive rents/terminations are unlawful; transparency is mandatory (reasoning, billing, official forms).

Tenancy agreement: content, deposit, handover

A tenancy can be oral — but always insist on written terms. Ensure clear details on parties, unit (address, flat), start date, net rent, utilities arrangement, deposit, termination dates and any index or stepped rent clauses.

  • Deposit: maximum of three months’ net rent for residential leases; must be held in a blocked bank account in the tenant’s name (interest belongs to you). Payout after move-out once claims are clarified.
  • Handover protocol: record condition, meter readings, and keys; keep photos/videos.
  • House rules/annexes: only binding if provided and agreed. Vague prohibitions aren’t automatically enforceable.
  • Pets: blanket bans are tricky; approval clauses are common. Small pets (e.g., hamsters) are usually allowed.

Utilities (Nebenkosten) explained

Utilities (operating costs) are only owed if explicitly agreed. Typical items are heating, hot water, common electricity and caretaking; administrative costs cannot simply be pushed into utilities. Billing can be on account with an annual statement or flat-rate (no back/extra payment, but also no upside).

Tips:
  • Large back payments? Review heating system, insulation and hot-water setup; request access to supporting documents.
  • Flat-rate too high? Adjustments must be transparent and well-reasoned.
  • In disputes: the conciliation authority can order the landlord to present evidence.

Defect rights & minor maintenance

If a defect reduces use or comfort, you may be entitled — depending on severity — to repair, a rent reduction, damages or rent deposit with the authority. Minor maintenance (small repairs such as bulbs, shower hose) is on the tenant — to a reasonable extent.

  • Report defects — immediately, in writing, with photos; set a reasonable repair deadline.
  • Reduction — for the period of impairment; the percentage depends on intensity.
  • Deposit with authority — if repairs don’t happen: pay into an official account (as instructed by the conciliation authority) and simultaneously notify the landlord.
  • Avoid misuse — unilateral deductions without the proper process are risky.

Rent increases: form & valid reasons

Rent increases are only valid if communicated on the official form, reasoned and served in time. Valid reasons include: increase of the reference rate, inflation (CPI), general cost increases, and value-enhancing investments. Pure maintenance or “cosmetics” do not justify a permanent increase.

  • Timing: notice must be given before the contractual termination date, at least 10 days before the notice period starts.
  • Challenge: within 30 days of receipt at the conciliation authority.
  • Evidence: for investments, a breakdown (value-enhancing vs. maintenance) is key.

Reference rate, inflation & adjustments

The mortgage reference rate is published by the federal government and underpins many adjustments. When it falls, a right to a rent reduction may arise; when it rises, increases may be justified — always with inflation and general costs offset appropriately. For indexed rents, the binding factor is the consumer price index (CPI) instead.

  • Applying for a reduction: write to the landlord with calculations (contract rate vs. current reference rate); tenant associations offer templates.
  • Indexed rent: adjusts per CPI as per contract — the reference rate usually doesn’t apply.
  • Stepped rent: fixed increases at defined dates; additional increases are heavily constrained.
  • Important: SNB policy rate ≠ mortgage reference rate — don’t mix them up.

Process for increases (illustrative)

Official form notice Check & evidence Watch deadlines Challenge (30 days)
Simplified overview — see law/authority for details.

Subletting, interim letting & short-term rentals

Subletting is generally permitted; the landlord’s approval is required and may only be refused for valid reasons (e.g., lack of transparency on conditions, excessive sub-rent, significant disadvantages for the landlord). Interim letting (fixed term) is usually fine when conditions are clear. Short-term rentals/Airbnb may require permits (city/canton), always need the landlord’s approval, and must respect house rules, occupancy and liability.

  • Inform in writing in advance: person(s), duration, rent, conditions.
  • The sub-rent must not significantly exceed your own rent (pro-rata).
  • Liability: the main tenant remains the landlord’s contractual counterparty.

Termination, protection & extensions

Ordinary terminations follow contractual deadlines/dates. Without special agreements, residential leases typically have 3 months’ notice to a local date. Terminations must be in writing; in Zurich, landlords use the official form. Abusive terminations (e.g., as retaliation for a defect notice or challenge) can be contested.

  • Form: handwritten signature; special rules for married couples/registered partners.
  • Deadlines: delivery must be on time (plan for postal transit).
  • Extension: in hardship cases the lease can be extended temporarily (balancing of interests).
  • Immediate termination: only for important reasons (e.g., severe breaches).

Deadlines, forms & mediation in Zurich

Strict form and deadline rules apply to increases/terminations. In disputes, the conciliation authority is the first stop. The procedure is low-threshold, quick and free; many cases settle.

  • Increase → notice on form, reasoning, deadline; challenge within 30 days.
  • Reduction → written request to the landlord; if refused → conciliation.
  • Defects → deposit rent as instructed by the authority; don’t “self-reduce”.

Practical examples & sample wording

Example A – Rent increase due to “renovation”
  • Notice on the official form; reason: renovation.
  • Check: is it value-enhancing (e.g., better insulation, new kitchen) or maintenance (repairs)?
  • For mixed projects: only the value-enhancing share can be passed on to rent.
Quick check
  • Request a cost breakdown.
  • Cross-check increase with neighborhood rents and the reference rate.
  • When in doubt, challenge within 30 days.
Example B – Defect & rent reduction
  • Heating repeatedly fails in winter; comfort severely affected.
  • Send written defect notice with deadline; if not fixed → deposit rent & claim reduction.
  • Collect documentation (photos, temperatures, correspondence).
Do & Don’t
  • Do: set deadlines cleanly, keep evidence, use the authority deposit process.
  • Don’t: make unilateral deductions without the formal process.

Template: rent reduction due to reference rate

Subject: Request for rent reduction based on mortgage reference rate

Dear Sir or Madam,
Based on the currently published mortgage reference rate and arts. 269/269a CO/VMWG, I request a reduction
of the net rent for the dwelling at [address], tenancy dated [date]. Please inform me of the adjusted rent as of the
earliest possible date. I am happy to answer any questions.

Kind regards,
[name, contact]

Checklists to tick off

Before signing the tenancy
  • All annexes received? (house rules, utilities list, index/stepped clauses, any side agreements)
  • Deposit set correctly? (max 3 net rents, blocked account in your name)
  • Typical termination dates/notice periods clear?
  • Condition & handover protocol prepared? (photos, meter readings)
When facing increases
  • Official form? Reasoned? In time?
  • Reference rate/CPI/investments plausible?
  • Neighborhood customary rent & benchmarks checked?
  • 30-day challenge deadline noted?
For defects
  • Reported in writing, deadline set, evidence saved?
  • Reduction/deposit requested correctly?
  • No unilateral cuts without process.

Further reliable sources

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