“Unlawful” termination by the landlord – a brief overview

In practice, it is not uncommon for a tenant (lessee) to be faced with a termination of their lease agreement that, at first glance, may appear “unlawful.” However, Swiss tenancy law provides various legal remedies for responding to a termination that does not comply with legal requirements. It is therefore important to distinguish between three different legal situations: null and void termination, invalid termination, and contestable termination. These are concepts that have different effects and, in some cases, require prompt action on the part of the tenant. This brief guide aims to clarify the main differences between these categories and to highlight some of the most common issues in practice.

Since the early 19th century, tenancy law has traditionally been characterized by a strong social component. In particular, the legislator intervenes when the free balance between the interests of the parties is at risk of being compromised.[1] The rules relating to nullity, invalidity, and contestation of termination are one expression of this protective function of tenancy law.

1.0 Null and void termination

1.1 Nullity in the strict sense

A termination is null and void (i.e. null in the strict sense) when it is vitiated by a formal or material defect provided for by law (Arts. 266l–266n CO according to Art. 266o CO). The nullity must be expressly stated in a legal provision or derive from the meaning and purpose of the applicable rule. The consequence of nullity is clear: the termination is considered never to have taken place and has no legal effect. The lease therefore continues without interruption. The tenant can invoke nullity at any time.

Swiss law lays down specific formal requirements for termination. It must be communicated in writing and, if it comes from the landlord, must be notified using an official form approved by the canton. This form must indicate the legal remedies available to the tenant, in particular the possibility of contesting the termination or requesting an extension of the lease (Art. 266l CO). A typical case of invalidity concerns the termination of a family home lease. If the lease agreement was concluded with two spouses (or registered partners) as tenants, the landlord must notify each of them separately of the termination (Art. 266n CO). This means that the termination must be communicated using two separate forms. If the landlord sends the notice of termination only to one of the spouses or partners, the notice is null and void, even if the official form has been used (Art. 266n CO). As with other declarations of intent requiring receipt, notification is deemed to have occurred when the communication reaches the recipient’s sphere of influence. In principle, therefore, the delivery of two forms to one spouse may also be considered valid for the other.[2] 

If several tenants are named in the lease agreement, according to the prevailing doctrine they constitute a simple partnership. In such a case, the notice of termination must be addressed to all tenants, who must be indicated as recipients on the official form (Art. 70 CO).[3] If this is not the case, the notice of termination must be repeated in its entirety with respect to all tenants; otherwise, the termination is null and void.[4]

1.2 Nullity in the broad sense (invalidity)

A notice of termination is considered invalid (in some cases also qualified as nullity in a broader sense) when, although it complies with the formal requirements provided by law (Arts. 266b–266o CO), it lacks the relevant legal or contractual basis, or when the conditions for termination provided by statutory provisions are not met. From a legal perspective, this therefore constitutes a form of relative nullity.

A practical example: the landlord communicates an extraordinary termination without the existence of the factual circumstances that justify such extraordinary termination.[5]

Unlike the aforementioned nullity in the strict sense, the declaration of the invalidity of the termination by the authorities or courts triggers the period during which termination is prohibited (the so-called “Sperrfrist”, see Art. 271a para. 1 lit. e CO), which may be advantageous for the tenant, since the landlord may, under certain conditions, be prevented from terminating the contract again during the three years following the end of conciliation or court proceedings relating to the lease.

Since the invalidity of a termination cannot always be clearly distinguished from its contestability, it is advisable, as a precaution, to challenge a termination considered invalid within the prescribed time limits in order to ensure effective protection.

2.0 Contestable termination

2.1 Contestability

Contestability means that a termination considered abusive may be annulled following a challenge. Indeed, the landlord’s freedom to terminate the lease relationship finds its limit in the principle of good faith as well as contractual loyalty.[6] Art. 271 CO constitutes the key provision and the general clause governing the contestability of a termination that is contrary to the principle of good faith, and it applies to both landlords and tenants. The lex specialis of Art. 271a CO sets out, in a non-exhaustive manner, several situations in which a termination by the landlord may be challenged by the tenant. Contestability therefore represents the first line of defence against an unjustified termination. Unlike a null or invalid termination, a challenged termination initially produces its effects. Protection is triggered only if the tenant (or the landlord, in the case of Art. 271 CO) challenges the termination within 30 days from notification.

For example, a termination may be contestable if it is issued because the tenant, who normally pays the rent on time, accumulated only a few days’ delay in payment.[7] Similarly, a termination may be considered abusive if it is motivated by noise caused by children, especially if, during the conclusion of the contract, the landlord had expressly indicated that the presence of children would not be a problem. Another typical case concerns a termination issued because the tenant expressed criticism regarding the dwelling or reported defects in the leased property.[8]

Case law also considers abusive, under certain circumstances, a termination motivated by isolated and minor incidents.[9] For example, occasionally leaving a bag of paper outside the door or having had a single argument with the caretaker does not normally constitute sufficient grounds to terminate the lease. In situations of minor importance, it is generally appropriate for the landlord first to issue a warning or reprimand.[10] Finally, a termination motivated by the sale of the property may also be contestable when the landlord claims that a higher sale price can be obtained if the apartment is vacant. In the absence of concrete evidence showing that selling the property without tenants would actually lead to a significantly higher price, the termination may be annulled due to an evident imbalance of interests.[11]

2.2 Extension of the lease

The second instrument for the protection of the tenant is the extension of the lease, provided for by Art. 272 CO, which may be invoked independently of the challenge to the termination. In practice, the tenant may request that the termination date of the contract be postponed if the termination causes serious hardship for the tenant or his or her family.

The authority must take into account the interests of the parties (Art. 272 para. 2 CO). These include, in particular, the circumstances that led to the conclusion of the contract and the content of the contract itself, as well as the duration of the lease relationship. The authority also evaluates the personal, health-related and economic situation of the parties. This includes, for example, age, state of health, marital status and professional situation, as well as the financial situation of the household.[12] Another element concerns the conduct of the parties. In the case of the tenant, this may include, for example, the efforts made to find new accommodation or certain habits of life that make relocation more difficult (as a rule, however, the tenant cannot be required to change his or her lifestyle, for example by changing jobs in order to improve his or her chances on the rental market).[13] 

On the other hand, the landlord’s interests are also examined, for example the possible need of the landlord or his or her close relatives or in-laws, as well as the urgency of such need.[14] 

Finally, the authority also takes into account the situation of the local housing or commercial premises market, for example on the basis of data relating to occupancy rates, the number of vacant dwellings or other indicators available in the area concerned.[15]

In conclusion, the tenant may request a first extension of the lease for a maximum duration of four years in the case of residential premises (Art. 272b para. 1 CO). If, at or near the expiry of the first extension, the circumstances justifying the measure are still present, or if the relevant conditions are still met, the tenant may also request a second extension of the lease.[16]

3.0 Conclusions

Lease relationships are an area of law characterized by numerous social-policy provisions which, at first glance, may appear unusual in what is otherwise a simple contractual relationship.

If you have any questions or need further information, please contact us at +41818510910 or via e-mail at info@nist-law.ch. We will be happy to assist you.

[1] Töngi, Mietrecht für die Praxis, 10th ed., 2022, ch. 1, p. 3.

[2] Decisions of the Swiss Federal Supreme Court (BGE) 118 II 42 consid. 3; 115 II 361 consid. 4c: The landlord cannot rely on the fact that the other spouse or partner became aware of the notice of termination in another way if the landlord did not notify the termination by means of two separate communications.

[3] Judgment of the Gerichtspräsidium of Aargau of 16 May 2011, consid. 2.1, in: mp 1/13, pag. 60, with further references; BGE 109 II 228, consid. 2b (explicitly confirmed for cohabitation); Müller, Das schweizerische Mietrecht Kommentar, 5th ed., 2025, N 39 vor 266-266o OR.

[4] BGE 140 III 491 consid. 4.2.1; Müller, Das schweizerische Mietrecht Kommentar, 5th ed., 2025, N 39 vor 266-266o OR.

[5] Due to tenant’s default in payment (Art. 257d CO); due to breach of the duty of care (Art. 257f CO); in the case of urgent personal need of the new landlord (Art. 261 CO); for serious reasons (Art. 266g CO); in the event of the tenant’s bankruptcy (Art. 266h CO), see Brändli, Mietrecht für die Praxis, 10th ed., 2022, ch. 27, p. 799.

[6] Swiss Federal Supreme Court judgment 4A_482/2014 of 20 January 2015 consid. 2.7.

[7] Higi/Bühlmann, ZK OR, 5a ed., 2022, N 82 segg. ad art. 271 CO; Thanei, Mietrecht für die Praxis, 10th ed., 2022, ch. 29, p. 888.

[8] Thanei, Mietrecht für die Praxis, 10th ed., 2022, ch. 29, p. 889.

[9] Thanei, Mietrecht für die Praxis, 10th ed., 2022, ch. 29, p. 890.

[10] Judgment of the Ticino Court of Appeal of 7 August 1997, in mp 2/98 S. 98 ff.

[11] Swiss Federal Supreme Court judgment 4A_485/2018 of 8 April 2019.

[12] Brändli, Mietrecht für die Praxis, 10th ed., 2022, ch, p. 942 segg.

[13] Brändli, Mietrecht für die Praxis, 10th ed., 2022, ch. 30, p. 949 segg.; BGE 116 II 446 consid. 3a (tenant’s efforts to find new accommodation); see Weber, BSK OR I, N 16 ad art. 272 CO (tenant’s lifestyle habits).

[14] Swiss Federal Supreme Court judgment 4A_673/2014 of 7 October 2016 consid. 3.2; Brändli, Mietrecht für die Praxis, 10th ed., 2022, ch. 30, p. 953 ff.

[15] BGE 142 III 442 consid. 3.2.; 136 III 82 consid. 2; Brändli, Mietrecht für die Praxis, 10th. ed., 2022, ch. 30, p. 947.

[16] Swiss Federal Supreme Court judgment 4A_545/2013 of 28 November 2013 consid. 4.2; Brändli, Mietrecht für die Praxis, 10th ed., 2022, ch. 30, p. 960.