Terminating a flat in a flatshare or as a married couple: who has to sign?

When several people live together in a flat or a house, the tenancy agreement is in the vast majority of cases signed jointly, as main tenants. What starts out harmonious and uncomplicated in everyday life turns into a legal trap the moment a termination comes up, a flatmate wants to move out or disagreements arise.

Anyone searching for "terminating a shared flat tenancy in Switzerland" or "tenancy termination signed by both" who wants to be on the safe side needs to know the strict formal requirements and liability risks of the Swiss Code of Obligations (CO) precisely.

This comprehensive expert guide answers every legal question around joint termination in shared flats, cohabiting couples and married couples.

1. The iron rule: the mandatory joint signature in multi-tenant agreements

Where several people are named in the tenancy agreement as main tenants, an unforgiving formal requirement of Swiss tenancy law applies — one that has already rendered countless terminations ineffective.

The joint declaration of intent is compulsory: in legal terms, a termination is a unilateral act subject to a formal requirement. In concrete terms: the termination letter must be signed by hand, on the original, by every main tenant named in the tenancy agreement.
The catastrophic consequences of a missing signature: if, in a typical three-person flatshare or an unmarried couple, only one person signs and the other flatmates leave out their signature, the entire termination is legally completely invalid. The property management or landlord does not even have to formally object — the tenancy simply continues unchanged for all parties, and the contractual payment obligations remain.

2. The special statutory case: married couples and registered partnerships (Art. 266m CO)

Anyone searching for "spouse terminating a flat in Switzerland" quickly runs into a statutory peculiarity. For married couples and registered partnerships, the Swiss Code of Obligations (in particular Art. 266m CO) protects the family home from unilateral decisions:

Protection of the shared family home: a spouse may terminate the shared tenancy only if the other spouse's express written consent is in place or an urgent, legally recognised exception applies.
The consequences of going it alone: without that written consent from the partner, a termination decided alone by the other spouse is absolutely null and void. The legislator wants to prevent one partner leaving the other homeless without warning or presenting them with a fait accompli.
An important difference from cohabitation: this strict provision applies exclusively to legally recognised marriages and registered partnerships. In an ordinary flatshare or for an unmarried cohabiting couple this particular statutory protection does not apply — there it is primarily the joint contract that makes signature by all parties compulsory.

3. The big financial trap: joint and several liability in tenancy law

Almost every professional tenancy agreement in Switzerland contains a clause on the dreaded joint and several liability. Anyone who wants to know what that means when a flatshare changes hands needs to understand how far it reaches.

What does joint and several liability actually mean? All main tenants named in the tenancy agreement are liable towards the landlord jointly and each of them individually for the entire financial obligations arising from the tenancy. In plain terms: if rent goes unpaid, service charges fall due or serious damage turns up after the move-out, the landlord can pick which tenant to recover the full amount from — even if that tenant always paid their own share on time.
The problem with a partial move-out (flatshare change): anyone searching for "flatmate moving out, changing the tenancy agreement" meets the greatest danger here. If a single flatmate wants to move out of a shared flat while the others stay, it is never legally sufficient for the departing tenant simply to send the management a short note or an email.
Liability that continues: as long as the tenancy agreement is not officially amended by mutual agreement with the landlord (by releasing the departing tenant in writing and, where applicable, admitting a new person), the flatmate who has moved out remains jointly and severally liable for the full rent and any damage — sometimes for years, even though they have long since been living somewhere else.
The only correct solution: it is essential to obtain an official contract amendment or a new tenancy agreement with the property management's consent, in which the departing tenant is explicitly and in writing released from joint liability.

4. Legally sound template: termination by several tenants (flatshare or couple)

When a rented flat with several main tenants (a flatshare, a family or a couple) is terminated, all names must appear in the letterhead and all parties must physically sign:

[First and last name tenant 1] & [First and last name tenant 2][Current street and number][Postcode and town]
[Name of the management or landlord][Street and number of the recipient][Postcode and town of the recipient]
[Your town], [date]
Subject: ordinary termination of the tenancy agreement Rented object: [street and number of the flat, floor]Object or reference number: [enter here if known]
Dear Sir or Madam
We hereby jointly terminate the tenancy agreement named above for the flat in question, in strict compliance with the contractual notice period, as of [end date of the contract, e.g. 30.09.2026] (or the next possible contractual date).
As this tenancy was entered into by several parties as joint main tenants, this termination letter is signed by hand on the original by all tenant parties involved, in line with the statutory formal requirements.
On receipt, please send us written confirmation of the exact end date as well as all the information we need about the handover of the flat and the return of the rental deposit, to our shared correspondence address.
Yours faithfully
_________________________________________[First and last name tenant 1]
_________________________________________[First and last name tenant 2]

5. Summary and check-list for multi-person households

Anyone living in a flatshare, with a partner or in a registered partnership should leave nothing to chance when it comes to termination and tenancy law:

No solo decisions: never draft a termination alone if several people are named in the contract.
Every signature, no exceptions: make sure that every single main tenant signs the physical original document.
Registered post, with a buffer: always send the finished dossier by registered letter so you have legally sound proof that it arrived on time.
Keep joint liability in view: when someone moves out partway, make scrupulously sure the tenancy agreement is officially amended, to avoid nasty financial surprises.

With this solid grounding, you will handle any flatshare termination and any change of tenant in Switzerland with complete confidence and legal certainty.

Terminating a flat in a flatshare or as a married couple: who has to sign?

This comprehensive expert guide answers every legal question around joint termination in shared flats, cohabiting couples and married couples.

1. The iron rule: the mandatory joint signature in multi-tenant agreements

The joint declaration of intent is compulsory: in legal terms, a termination is a unilateral act subject to a formal requirement. In concrete terms: the termination letter must be signed by hand, on the original, by every main tenant named in the tenancy agreement.
The catastrophic consequences of a missing signature: if, in a typical three-person flatshare or an unmarried couple, only one person signs and the other flatmates leave out their signature, the entire termination is legally completely invalid. The property management or landlord does not even have to formally object — the tenancy simply continues unchanged for all parties, and the contractual payment obligations remain.

2. The special statutory case: married couples and registered partnerships (Art. 266m CO)

Protection of the shared family home: a spouse may terminate the shared tenancy only if the other spouse's express written consent is in place or an urgent, legally recognised exception applies.
The consequences of going it alone: without that written consent from the partner, a termination decided alone by the other spouse is absolutely null and void. The legislator wants to prevent one partner leaving the other homeless without warning or presenting them with a fait accompli.
An important difference from cohabitation: this strict provision applies exclusively to legally recognised marriages and registered partnerships. In an ordinary flatshare or for an unmarried cohabiting couple this particular statutory protection does not apply — there it is primarily the joint contract that makes signature by all parties compulsory.

3. The big financial trap: joint and several liability in tenancy law

What does joint and several liability actually mean? All main tenants named in the tenancy agreement are liable towards the landlord jointly and each of them individually for the entire financial obligations arising from the tenancy. In plain terms: if rent goes unpaid, service charges fall due or serious damage turns up after the move-out, the landlord can pick which tenant to recover the full amount from — even if that tenant always paid their own share on time.
The problem with a partial move-out (flatshare change): anyone searching for "flatmate moving out, changing the tenancy agreement" meets the greatest danger here. If a single flatmate wants to move out of a shared flat while the others stay, it is never legally sufficient for the departing tenant simply to send the management a short note or an email.
Liability that continues: as long as the tenancy agreement is not officially amended by mutual agreement with the landlord (by releasing the departing tenant in writing and, where applicable, admitting a new person), the flatmate who has moved out remains jointly and severally liable for the full rent and any damage — sometimes for years, even though they have long since been living somewhere else.
The only correct solution: it is essential to obtain an official contract amendment or a new tenancy agreement with the property management's consent, in which the departing tenant is explicitly and in writing released from joint liability.

4. Legally sound template: termination by several tenants (flatshare or couple)

When a rented flat with several main tenants (a flatshare, a family or a couple) is terminated, all names must appear in the letterhead and all parties must physically sign:

[First and last name tenant 1] & [First and last name tenant 2][Current street and number][Postcode and town]
[Name of the management or landlord][Street and number of the recipient][Postcode and town of the recipient]
[Your town], [date]
Subject: ordinary termination of the tenancy agreement Rented object: [street and number of the flat, floor]Object or reference number: [enter here if known]
Dear Sir or Madam
We hereby jointly terminate the tenancy agreement named above for the flat in question, in strict compliance with the contractual notice period, as of [end date of the contract, e.g. 30.09.2026] (or the next possible contractual date).
As this tenancy was entered into by several parties as joint main tenants, this termination letter is signed by hand on the original by all tenant parties involved, in line with the statutory formal requirements.
On receipt, please send us written confirmation of the exact end date as well as all the information we need about the handover of the flat and the return of the rental deposit, to our shared correspondence address.
Yours faithfully
_________________________________________[First and last name tenant 1]
_________________________________________[First and last name tenant 2]

5. Summary and check-list for multi-person households

Anyone living in a flatshare, with a partner or in a registered partnership should leave nothing to chance when it comes to termination and tenancy law:

No solo decisions: never draft a termination alone if several people are named in the contract.
Every signature, no exceptions: make sure that every single main tenant signs the physical original document.
Registered post, with a buffer: always send the finished dossier by registered letter so you have legally sound proof that it arrived on time.
Keep joint liability in view: when someone moves out partway, make scrupulously sure the tenancy agreement is officially amended, to avoid nasty financial surprises.

With this solid grounding, you will handle any flatshare termination and any change of tenant in Switzerland with complete confidence and legal certainty.