← Blog

Swiss Tenancy Law: The 10 Most Important Rules for Landlords

·12 min read

You have just bought your first investment property. The apartments are rented out, the cashflow looks good. But then tenant Keller gets in touch. She has discovered water damage in the bathroom and demands immediate repair. At the same time, she threatens a rent reduction because the defect has allegedly existed for three weeks. You think: that cannot be right, the apartment was in perfect condition when I bought it.

Welcome to the reality of Swiss tenancy law. It strongly protects tenants, imposes clear obligations on landlords, and penalises ignorance. Those who do not know the rules risk invalid terminations, challengeable rents, and expensive proceedings before the conciliation authority.

This article summarises the 10 most important rules you need to know as a landlord in Switzerland. Not as a legal textbook, but as a practical guide that helps you avoid typical mistakes.

Rule 1: Formal Requirements for Termination

Terminating a tenancy in Switzerland is strictly formalised. A termination by email, WhatsApp, or informal letter is invalid. Period.

What You Need to Observe

  • Official form: You must use the form prescribed by the canton. It is named differently depending on the canton but always serves the same function: it informs the tenant of their rights and the option to challenge the termination.

  • Separate delivery for married couples or registered partners: If both partners are on the lease or the apartment is used as a family home, the termination must be delivered to each partner separately. A single termination addressed to "the Meier family" is invalid.

  • Registered mail: The termination must be sent by registered mail. Keep the registration receipt. If the tenant does not collect the registered mail, the termination is still considered delivered, provided they received the collection notice.

Common Mistake

You terminate the tenant verbally during the apartment handover and send the form later. The form must reach the tenant within the deadline, not the verbal notice.

Rule 2: Notice Periods and Termination Dates

Swiss tenancy law has clear deadlines, and they are non-negotiable (except in the tenant's favour).

Statutory Minimum Periods

  • Apartments: 3 months' notice, termination only on the customary local date (typically end of March, end of June, end of September, or end of December, depending on canton and municipality).

  • Furnished rooms and parking spaces: 2 weeks' notice to the end of a month.

  • Commercial premises: 6 months' notice on a customary local date.

What Does "Customary Local Date" Mean?

The customary termination dates vary by municipality. In Zurich, they are typically 31 March and 30 September. In other municipalities, there is only one or up to four dates per year. Always check the local provisions.

Fixed-Term Leases

With fixed-term contracts, the tenancy ends automatically on the agreed date. No termination is needed. But be careful: if the tenant remains in the apartment after the term expires and you take no action, the contract automatically becomes open-ended.

Rule 3: Rent Challenges by the Tenant

Every tenant has the right to challenge the initial rent or a rent increase before the conciliation authority. This is not an exotic special case but common practice in Switzerland.

Initial Rent

The tenant may challenge the initial rent within 30 days of taking over the apartment if they believe the rent is abusive. A rent is considered abusive if the landlord earns an excessive return or if the rent is based on an obviously inflated purchase price.

For investors, this is particularly relevant: if you buy a property at a high price and set rents accordingly, the tenant can challenge the rent. The conciliation authority will then examine whether the purchase price and the resulting return are reasonable.

Practical Tip

Document the previous tenant's rent. If you increase the rent by more than 10 to 15 percent at a tenant changeover, the risk of a challenge rises significantly.

Rule 4: The Reference Interest Rate

The mortgage reference interest rate is the central instrument for rent adjustments in Switzerland. It is published quarterly by the Federal Office for Housing and is based on the volume-weighted average interest rate of all outstanding mortgages.

How Does It Work?

  • When the reference rate falls, the tenant has a right to a rent reduction. Per quarter-point decrease, the reduction is approximately 2.91 percent.

  • When the reference rate rises, the landlord may increase the rent. Per quarter-point increase, the adjustment is approximately 3 percent.

What Landlords Need to Know

You must take action. When the reference rate rises, you may increase the rent, but only using the official form and within the deadlines (typically for the next termination date, meaning with 3 months' advance notice). When the reference rate falls, the tenant must request the reduction. You are not obligated to lower the rent on your own initiative.

The tax implications of rent adjustments on your investment property are complex. The article on taxes for investment properties explains the details.

Rule 5: Defect Notification and Repair

Back to tenant Keller and her water damage. The obligation to remedy defects is one of the core duties of the landlord.

Your Obligations

  • Minor defects (dripping tap, burnt-out light bulb): The tenant must fix these themselves. The threshold varies by canton, typically CHF 150 to CHF 200 per repair.

  • Medium and major defects (broken heating, water damage, leaking windows): You must remedy these within a reasonable timeframe. What is "reasonable" depends on the urgency. A heating failure in winter must be fixed immediately; a cosmetic defect can wait a few weeks.

What Happens If You Do Not Respond?

The tenant has three options:

  1. Rent reduction: They can reduce the rent by the amount corresponding to the diminished value of the apartment. However, they must first request in writing that you remedy the defect.

  2. Substitute performance: They can have the defect fixed themselves and invoice you for the costs. Again, they must have asked you first.

  3. Rent deposit: They can deposit the rent with the responsible authority, putting pressure on you.

Practical Tip

Always respond to defect notifications in writing and promptly. Even if you cannot fix the defect immediately, show the tenant that you take the matter seriously. Document everything. Photos, tradesperson invoices, email correspondence. This protects you in any dispute.

Rule 6: Ancillary Cost Accounting

The ancillary cost statement is a frequent point of dispute between landlords and tenants. The law is clear here, but practice is often sloppy.

Basic Rules

  • Only agreed ancillary costs: You may only pass on the ancillary costs that are expressly listed in the lease. If the contract states "ancillary costs flat rate CHF 200," you cannot demand additional payment, even if the actual costs are higher.

  • Advance payments: With advance payments (Akonto), you must account annually and present the receipts to the tenant on request. The accounting must be completed within a reasonable period after the end of the billing period (typically 6 to 12 months).

  • No management costs: Your own management costs are not recoverable ancillary costs. Neither are renewal fund contributions for condominium ownership (Stockwerkeigentum).

Typical Mistakes

  1. You bill items not listed in the lease.
  2. You delay the accounting by two years and demand back-payments for long-past periods.
  3. You do not provide receipts when the tenant asks.

All of these mistakes can result in you being stuck with the costs.

Rule 7: Value-Enhancing Investments vs. Maintenance

This distinction is gold for investors because it determines whether you may raise the rent after a renovation.

Maintenance (value-preserving)

Repairs and renewals that restore the original condition count as maintenance. Examples: replacing a boiler, painting the facade, exchanging defective windows. These costs can be claimed as a tax deduction, but they do not entitle you to a rent increase.

Value-Enhancing Investments

Investments that increase the living quality count as value-enhancing. Examples: replacing the kitchen with a higher-quality one, adding a balcony, Minergie renovation. With these investments, you may pass on a reasonable portion to the rent.

The Rule of Thumb

For comprehensive renovations, typically 50 to 70 percent of the costs are considered value-enhancing. The remainder is maintenance. This split is not legally fixed but derived from case law and practice.

Practical Tip

Plan major renovations strategically. If you know a tenant changeover is coming, you can combine the renovation with the changeover and freely set the new rent (subject to the abuse threshold). During an ongoing tenancy, you need the official form and a solid justification for every rent increase.

Rule 8: Termination for Personal Use

You would like to use an apartment in your investment property for yourself or a family member? That is possible in principle, but comes with hurdles.

Requirements

  • Urgent personal need: You must demonstrate that the personal need is urgent. "I would like to use the apartment occasionally" is not sufficient. You or your close relative must genuinely and promptly intend to move in.

  • No abusive termination: The termination may not serve as a pretext to get rid of an unwanted tenant. If you terminate for personal use but then re-rent the apartment at a higher price, this may be considered abusive.

Challenge by the Tenant

The tenant may challenge the termination within 30 days at the conciliation authority. They can request an extension of the tenancy if the termination would cause them particular hardship. The extension can be up to 4 years (for commercial premises, up to 6 years).

Practical Tip

If you are buying a property and intend to claim personal use, inform yourself about the current tenant situation beforehand. Long-term tenants, elderly persons, and families with children enjoy stronger protection against termination in practice.

Rule 9: The Conciliation Authority

The conciliation authority is the first port of call for tenancy disputes. Before you or your tenant can go to court, you must go through the conciliation process.

How Does the Procedure Work?

  1. The applicant (tenant or landlord) files a request with the relevant conciliation authority.
  2. The conciliation authority invites both parties to a hearing.
  3. The authority attempts to reach a settlement.
  4. If no settlement is reached, the authority issues authorisation to sue (for amounts above CHF 2'000) or renders a decision (for amounts up to CHF 2'000).

What Landlords Should Know

  • The procedure is free of charge for both parties.
  • You must appear in person or be represented by an authorised person.
  • The conciliation authority is not a formality. Many cases are resolved here, and the settlement proposals follow established case law.
  • Even if you are in the right: willingness to compromise saves time and nerves. Court proceedings can take months and incur costs.

Rule 10: The Form Requirement for Rent Changes

Every rent increase must be communicated on the official form. This obligation is often underestimated, and violations have drastic consequences.

What the Form Must Include

  • The previous and new rent
  • The date from which the new rent applies
  • The justification for the increase (reference rate, inflation, cost increases, value-enhancing investments)
  • Notice of the tenant's right to challenge

Consequences of Formal Errors

A rent increase without the official form is void. That means: it does not legally exist. The tenant can reclaim the difference, even retroactively. Even if the tenant paid the increased rent for years without objecting.

Practical Tip

Have rent adjustments handled by an experienced property management company. The cost is minimal compared to the risk of a void rent increase. If you self-manage, obtain the current forms from the relevant cantonal office.

Bonus: Three Golden Rules for Everyday Landlording

Beyond the legal details, there are three principles that make your life as a landlord easier:

1. Document everything. Every agreement, every defect notification, every repair. In writing, with a date. In a dispute, what matters is what you can prove.

2. Communicate proactively. Inform your tenants about planned works, rent adjustments, and other changes early. People who are surprised react defensively.

3. Invest in the relationship. Satisfied tenants stay longer, take better care of the apartment, and cause less vacancy. The best tenant is the one you already have.

Conclusion

Swiss tenancy law is tenant-friendly, complex, and formalistic. As a landlord, you can live with it if you know the rules and work carefully. Most problems arise not from bad intentions but from ignorance. Those who observe the formal requirements, respond promptly to defects, and carry out rent adjustments correctly have little to fear.

Frequently Asked Questions

Can I simply terminate my tenant's lease in Switzerland?

No. A termination must be issued on the official form, observe the statutory deadlines and dates, and must not be abusive. For married couples or registered partners, the termination must be delivered to each partner separately. The tenant may challenge the termination within 30 days at the conciliation authority.

How can I increase the rent as a landlord?

A rent increase is possible when the reference interest rate rises, with inflation, increased maintenance costs, or value-enhancing investments. The increase must be communicated on the official form, include a justification, and observe the notice period. Without the form, the increase is void.

Who pays for repairs in the rental apartment?

Minor repairs (small maintenance up to approximately CHF 150 to CHF 200) must be paid for by the tenant. All larger defects not caused by the tenant must be remedied by the landlord. The obligation to remedy defects is a core duty of the landlord and cannot be contractually waived.

What happens at the conciliation authority?

The conciliation authority attempts to reach a settlement between tenant and landlord. The procedure is free of charge and mandatory before court proceedings. For amounts up to CHF 2'000, the authority can render a binding decision. For higher amounts, it issues authorisation to sue, with which the parties can proceed to the tenancy court.

Calculate the return on your property now

Free. No registration required.

Analyze now