A Swiss cohabitation agreement requires no particular form. What it should cover, which parts still need a statutory form, and why Art. 533 para. 1 OR is expensive without one.
For married couples the legislator has provided a default: those who agree nothing are subject to the ordinary matrimonial property regime, and when it ends it is clear how the assets are divided. For unmarried couples the legislator has provided nothing. The Swiss Civil Code (ZGB) contains no rules on cohabitation — no matrimonial property law, no duty of maintenance, no inheritance rights.
What the statute leaves open is filled in by the courts if a dispute arises — using rules from partnership law that were never designed for couples. This is exactly where the cohabitation agreement comes in. It is not a formality but the only basis an unmarried couple can rely on when they separate.
Concluding it is undramatic: under Art. 11 para. 1 OR (Swiss Code of Obligations) a cohabitation agreement requires no particular form. No notarisation, no authority, no register. The entire effort lies in drafting the substance — and that is where the difference lies between an agreement that holds up and one that merely reassures.
Key points at a glance
| Question | Answer |
|---|
| Form | none required (Art. 11 para. 1 OR); written form strongly recommended |
| Notarisation | not necessary |
| Costs | no notarial or registration fees; the effort lies solely in drafting |
| Without an agreement | no matrimonial property law — depending on the circumstances, the rules on the simple partnership (BGE 108 II 204) |
| Core risk | Art. 533 para. 1 OR: equal shares irrespective of the nature and size of the contribution |
| Typical content | inventory, cost sharing, joint purchases, property, loans, compensation for reduced employment, powers of attorney, separation |
| Cannot be regulated | inheritance rights, child maintenance, occupational pension entitlements, civil status |
| Accompanying documents | will or contract of succession, declaration of beneficiary to the pension fund, advance care directive |
Why a gap remains without an agreement
Cohabitation is not a civil status. Art. 8 lit. d of the Civil Status Ordinance (ZStV) lists the civil statuses recorded in the register exhaustively; cohabitation is not among them. The Civil Code contains no rules on it. A series of consequences follows:
- No mutual duty of maintenance or support. Art. 159 ZGB applies expressly to spouses only.
- No matrimonial property law and therefore no statutory equalisation of assets on separation.
- No statutory inheritance rights. The order of succession under Art. 457 et seq. and Art. 462 ZGB covers descendants, the parental and grandparental lines and surviving spouses and registered partners — not the cohabiting partner.
- No AHV survivors' pension. Art. 23, 24 and 24a AHVG link widows' and widowers' pensions exclusively to marriage. Only the orphan's pension under Art. 25 AHVG is independent of civil status.
- No power of representation in financial matters. The statutory right of representation under Art. 374 ZGB is reserved to spouses and registered partners.
- Separate taxation. The aggregation of incomes under Art. 9 DBG applies only to spouses and registered partners.
One exception is frequently overlooked: in medical matters there is a statutory right of representation. Under Art. 378 para. 1 no. 4 ZGB, decisions on medical measures may be taken by the person who shares a household with the incapacitated person and provides them with regular personal support — ranking immediately after the spouse and ahead of children and parents.
Obligations are treated differently. In BGE 141 I 153 the Federal Supreme Court confirmed that taking a cohabitation contribution into account in social assistance is neither arbitrary nor unequal treatment where the cohabitation is stable; it is expressly irrelevant whether the financially capable partner declares a willingness to pay. In the Canton of Zurich a cohabitation counts as stable after more than two years, or where the couple runs a household with joint children. In terms of obligations, cohabitation is treated like a marriage; in terms of rights, like a relationship that does not legally exist.
The default rule: the simple partnership
Where there is no agreement, the Federal Supreme Court fills the gap — but not with matrimonial property law. In BGE 108 II 204 it expressly rejected applying matrimonial property principles by analogy and held that whether the rules on the simple partnership apply must be decided on the specific circumstances. BGE 109 II 228 applies its liquidation provisions where both partners worked together towards an economic result.
The threshold is low. Under Art. 530 para. 1 OR a partnership exists where two persons agree to combine their efforts or resources to achieve a common purpose. No deed and no intention to found a business is needed. A jointly financed house conversion, a business built up together or jointly acquired assets are enough. Art. 531 OR obliges the partners to make contributions — in money, assets, claims or labour.
Art. 533 para. 1 OR — the most expensive provision
The sentence that moves the most money in practice is Art. 533 para. 1 OR: in the absence of any other agreement, each partner has an equal share in profit and loss — irrespective of the nature and size of their contribution.
An example in figures:
| Partner A | Partner B |
|---|
| Contribution to joint assets | CHF 96'000 (80 %) | CHF 24'000 (20 %) |
| Expectation on separation | CHF 96'000 | CHF 24'000 |
| Result under Art. 533 para. 1 OR | CHF 60'000 | CHF 60'000 |
| Difference | − CHF 36'000 | + CHF 36'000 |
Whoever contributed more must prove the differing quota — or record it in the agreement. That is precisely what the contract is for: Art. 533 para. 1 OR applies expressly only in the absence of any other agreement.
Three further consequences of the simple partnership regularly come as a surprise:
- Joint and several liability towards third parties. Where the partners act jointly, Art. 544 para. 3 OR makes each liable for the whole.
- Dissolution on death. Under Art. 545 para. 1 no. 2 OR the partnership ends on the death of a partner. The surviving partner then faces a settlement with the heirs without being an heir.
- No return of assets contributed. In liquidation, Art. 548 and 549 OR give a claim only to the value of the asset contributed, not to the asset itself. Whoever brought the piano or the car into the relationship may receive money instead of the object. Under Art. 550 OR the settlement is also carried out by all partners jointly — where they cannot agree, the only remaining route is the court.
Form: none required, with exceptions
Under Art. 11 para. 1 OR contracts require a particular form only where the law prescribes one. For the cohabitation agreement it does not. It is valid without form, including orally.
In practice this helps little. An agreement intended to have effect on separation must be provable, and it is provable only if it is written, dated and signed by both, with a copy for each. Unlike a marital property agreement, which the law requires to be publicly notarised, written form here is a matter of prudence rather than validity.
Individual elements nonetheless require a form — regardless of what the cohabitation agreement says:
| Element | Required form | Provision |
|---|
| Transfer of real property | public notarisation | Art. 657 para. 1 ZGB |
| Disposition on death, unilaterally revocable | holograph will (entirely handwritten, dated, signed) or public notarisation with two witnesses | Art. 498, 505 ZGB |
| Disposition on death with binding effect | contract of succession in the form of a public testamentary disposition, simultaneous declaration before the notary and two witnesses | Art. 512 ZGB |
| Representation in case of incapacity | advance care directive, handwritten or publicly notarised | Art. 361 ZGB |
| Beneficiary status in occupational pension provision | declaration to the pension fund in accordance with its regulations | — |
| Child maintenance | approval by the child protection authority | Art. 287 para. 1 ZGB |
The contract of succession has one advantage over a will that often decides the matter for unmarried couples: it is binding. Under Art. 494 para. 3 ZGB later dispositions that contradict it can be challenged. A will, by contrast, can be changed unilaterally by the survivor at any time.
What the agreement should cover
Inventory
The foundation. Which assets did each partner bring in, which belong to one of them alone, which are jointly owned? After ten years of a shared household this can hardly be reconstructed without a record: receipts are missing, purchases have been mixed, replacements obscure the origin. The inventory belongs in an annex to the agreement and should be updated periodically.
Running costs
Rent, utilities, household, insurance, vehicle: a sensible allocation key follows the income situation and describes what happens when it changes — for instance on unemployment or a reduced workload. Equally important is the clarification that contributions to running costs do not create claims against the other partner's assets. Without it, that is exactly what the dispute is about.
Joint purchases
Furniture, vehicles, electronics, equipment. Three points need to be settled: who owns the item, how it is valued on separation, and who may take it over. Without a clause Art. 533 para. 1 OR applies — and in liquidation Art. 548 and 549 OR give a claim to the value only in any case.
Property
The largest source of dispute and the most common reason for an agreement. Where both buy together, the co-ownership shares must be entered in the land register; they should correspond to the actual financing contributions. The agreement adds what the land register does not show: the treatment of amortisation and value-enhancing investments, the valuation method on separation, pre-emption and take-over rights, and the deadlines for paying out the departing partner. The transfer of ownership itself always requires public notarisation under Art. 657 para. 1 ZGB.
Loans between the partners
Anyone who gives the other money should record whether it is a loan, a contribution to living costs or a gift. Without evidence a loan regularly turns into a gift on separation — simply because the opposite cannot be proven. Amount, purpose, repayment, any interest and the due date on separation should be set out.
Compensation for reduced employment due to childcare
The most important point in the whole agreement. Whoever reduces their employment to care for children loses three times over: current income, capacity to save and contributions to occupational pension provision. For spouses, matrimonial property law and pension equalisation absorb at least part of this. In cohabitation there is no statutory equalisation at all. Without an agreement the caring partner bears the loss alone.
This can be caught contractually: through ongoing compensation payments, through contributions to the caring partner's pillar 3a, through a share in the jointly built-up assets, or a combination. What matters is that the clause is quantifiable rather than a declaration of intent.
Powers of attorney
For illness you need a power of attorney that survives the onset of incapacity, plus banking authorisations. These do not replace the advance care directive under Art. 361 ZGB but supplement it: the directive covers personal care, asset management and representation in legal transactions and is validated by the adult protection authority under Art. 363 ZGB when incapacity occurs.
Separation clause
The section nobody wants to write and everyone needs. It should settle: who leaves the flat and within what period, how joint assets are valued and as at which date, within what deadlines payments are made, and what happens to the joint tenancy agreement, to accounts and to standing orders. A clause drafted in mutual goodwill is almost always fairer than one negotiated in conflict.
What the agreement cannot do
| Assumption | Reality |
|---|
| «We appoint each other as heirs» | Only a will (Art. 498, 505 ZGB) or a contract of succession (Art. 512 ZGB) has effect under inheritance law. The cohabitation agreement does not change the statutory order of succession. |
| «We settle the pension fund in the contract» | Entitlements arise only under the pension fund's regulations. Art. 20a para. 1 lit. a BVG is a discretionary provision. |
| «We waive child maintenance» | Not permissible. Under Art. 289 para. 1 ZGB the claim belongs to the child; under Art. 287 para. 1 ZGB maintenance agreements bind the child only once approved by the child protection authority. |
| «We agree on joint parental responsibility» | Under Art. 298a ZGB it arises only by a joint declaration before the civil registry office or the child protection authority. Until then parental responsibility rests with the mother alone (Art. 298a para. 5 ZGB). If one parent refuses, the other may apply to the authority under Art. 298b ZGB. |
| «The contract gives us a civil status» | No. Art. 8 lit. d ZStV lists the civil statuses exhaustively and cohabitation is not among them. AHV survivors' pensions under Art. 23, 24 and 24a AHVG therefore remain excluded. |
Under inheritance law the scope has nonetheless widened. Since the succession law reform of 1 January 2023 (AS 2021 312) the compulsory portion of descendants is only half of the statutory entitlement instead of three quarters (Art. 471 ZGB), and the parents' compulsory portion has been abolished (Art. 470 para. 1, Art. 471 ZGB). The freely disposable portion of an unmarried testator with children has thus risen from one quarter to one half. Where a compulsory portion is infringed, the entitled heirs may bring an action in abatement under Art. 522 ZGB.
The four documents
A cohabitation agreement alone is not enough. Full protection normally requires four building blocks, and they must be aligned with one another.
| # | Document | Covers | Form |
|---|
| 1 | Cohabitation agreement | assets, costs, compensation, separation | none required (Art. 11 para. 1 OR), written form recommended |
| 2 | Will or contract of succession | estate | Art. 498, 505 ZGB or Art. 512 ZGB |
| 3 | Declaration of beneficiary to the pension fund | occupational pension provision | as required by the fund's regulations |
| 4 | Advance care directive | representation in case of incapacity | handwritten or publicly notarised (Art. 361 ZGB) |
On the third point: Art. 20a para. 1 lit. a BVG allows a pension fund to designate as beneficiary the person who lived in an uninterrupted cohabitation with the insured for the five years up to death, or who must support joint children. It is a discretionary provision and applies under Art. 49 para. 2 no. 3 BVG to the extra-mandatory range as well. In BGE 137 V 383 the Federal Supreme Court confirmed that pension funds may define the circle of beneficiaries more narrowly than the statute. Check your fund's regulations before relying on an entitlement.
### The most expensive mistake A will does not create beneficiary status in occupational pension provision. In BGE 142 V 233 the Federal Supreme Court held that a testamentary disposition appointing the cohabiting partner as heir does not permit the conclusion that a beneficiary designation under occupational pension law was intended — not even where she is appointed sole heir. An express reference to the relevant provisions of the pension fund regulations, or at least to occupational pension provision, is required. Anyone who wants to protect their partner must submit the declaration of beneficiary the fund requires — in addition to the will, not instead of it.
For pillar 3a the position is more favourable: under Art. 2 para. 1 lit. b BVV3 the cohabiting partner ranks in category 2 on an equal footing with the direct descendants, after five years of uninterrupted cohabitation or where they support joint children. The allocation within that rank can be specified under Art. 2 para. 2 BVV3.
A word on inheritance tax: it is governed cantonally and the range is considerable. It runs from full exemption of the cohabiting partner — in Schwyz, Graubünden and Zug, among others — through exemption after a qualifying period, as in Lucerne after two years and Uri after five, to the full non-relative tariff. Zurich grants an allowance of CHF 50'000 after five years in a shared household. Check the rules of your canton of residence specifically before drafting any succession planning.
Why templates fail
Templates serve a purpose: they show which topics exist at all. As a checklist they are useful. As a contract they fail on four points.
First: the decisive part consists of figures. Contribution quotas, valuation methods, compensation amounts, deadlines — these are the details that count in a dispute, and no template knows them. A clause such as «the partners share the costs proportionately» merely postpones the argument.
Second: departing from Art. 533 para. 1 OR must be express and quantified. The statutory rule applies unless something else has been agreed, and a general fairness clause is not something else.
Third: a template covers only one of four documents. The will or contract of succession, the notification to the pension fund and the advance care directive remain open — and the pension notification in particular is replaced by nothing else, as BGE 142 V 233 shows.
Fourth: elements requiring a statutory form come to nothing. Agreeing in a template that the surviving partner shall receive the flat produces no effect under inheritance law — that requires a will or a contract of succession, and the transfer of ownership itself requires public notarisation under Art. 657 para. 1 ZGB.
The test is simple: if an uninvolved reader cannot work out from the agreement who receives how much on separation, the agreement settles nothing.
International couples
Where partners hold different nationalities, own assets abroad or have moved to Switzerland from another country, a second layer applies. The cohabitation agreement remains free of form, but three questions belong before the drafting.
Which law applies does not depend on the wording of the contract alone. In cross-border situations the applicable law and the competent court should be clarified in advance — that determines whether the agreement will be applied at all.
Whether a Swiss disposition is recognised abroad is the second question. A will or contract of succession drawn up here must also take effect where the assets are located; many legal systems do not recognise the contract of succession, and real property abroad is frequently governed by its own rules.
Immigration law, finally, ties family reunification to marriage. The statutory entitlement under Art. 42 AIG (Foreign Nationals and Integration Act; family members of Swiss citizens) and Art. 43 AIG (family members of holders of a settlement permit) covers foreign spouses and unmarried children under 18 — cohabiting partners are not included. Where the relationship is stable and comparable to a marriage, however, an entitlement may arise from Art. 8 ECHR, the right to respect for family life; that route lies outside the AIG provisions named above and requires an assessment of the individual case. A cohabitation agreement creates no residence right in itself. It can, however, serve as evidence of the stability and seriousness of the relationship where an application is based on Art. 8 ECHR.
In practice a bilingual version is advisable where one party is not fully comfortable in the contract language — with a clause stating which version prevails in case of doubt.
When legal advice is worthwhile
- A shared property with unequal financing contributions — by far the most common source of dispute, and the point where Art. 533 para. 1 OR moves the largest amounts
- One partner reduces employment for childcare — there is no statutory equalisation
- A joint business, or work in the other partner's business — a simple partnership is particularly close at hand here
- Substantial assets — the interaction of the cohabitation agreement, inheritance law and cantonal inheritance tax determines the net outcome
- International situations — applicable law, foreign assets, recognition of dispositions
- An existing will dating from before 2023 — the new compulsory portions open up more room, and older arrangements rarely use it
- Children from earlier relationships — compulsory portions and patchwork situations
- An existing agreement based on a template — reviewing it is usually quicker than drafting anew
Sobiera Legal Consulting drafts cohabitation agreements and the accompanying documents — will or contract of succession, declaration of beneficiary and advance care directive — including in international situations, in German, English, French, Ukrainian and Russian. The initial consultation is billed on a time-spent basis; further work depends on the scope of the mandate.
Related topics
Sources
- Code of Obligations OR (SR 220), Art. 11, 530, 531, 533, 544, 545, 548–550
- Civil Code ZGB (SR 210), Art. 159, 287, 289, 298a, 298b, 361, 363, 374, 378, 457 et seq., 462, 470, 471, 494, 498, 505, 512, 522, 657 — fedlex.admin.ch
- Civil Status Ordinance ZStV (SR 211.112.2), Art. 8 lit. d
- Federal Act on Occupational Pension Provision BVG (SR 831.40), Art. 20a para. 1 lit. a, Art. 49 para. 2 no. 3
- Ordinance on the Tax Deductibility of Contributions to Recognised Pension Schemes BVV3 (SR 831.461.3), Art. 2
- Federal Act on Old-Age and Survivors' Insurance AHVG (SR 831.10), Art. 23, 24, 24a, 25
- Federal Act on Direct Federal Taxation DBG (SR 642.11), Art. 9
- Foreign Nationals and Integration Act AIG (SR 142.20), Art. 42, 43
- ECHR (SR 0.101), Art. 8
- Federal Act of 18 December 2020 amending the ZGB (succession law), AS 2021 312, in force since 1 January 2023
- BGE 108 II 204 · BGE 109 II 228 · BGE 137 V 383 · BGE 141 I 153 · BGE 142 V 233
- Cantonal inheritance tax legislation (including SZ, GR, ZG, LU, UR, ZH)
- Social Assistance Manual of the Canton of Zurich, ch. 6.2.03
Status: August 2026. This article provides an overview and does not replace legal advice in an individual case. Cantonal rules on taxation and social assistance differ; the law at the place of residence governs. In cross-border situations the applicable law must additionally be examined.
Frequently asked questions
What is a cohabitation agreement?
An agreement by which an unmarried couple organises their financial relationship themselves — an inventory of what each brought in, how running costs are shared, who owns joint purchases, loans between the partners, compensation payments and what happens on separation. Because the Swiss Civil Code (ZGB) contains no rules on cohabitation, this contract is the only basis a couple can rely on if a dispute arises.
Does a cohabitation agreement have to be notarised in Switzerland?
No. Under Art. 11 para. 1 OR (Swiss Code of Obligations) a contract requires a particular form only where the law prescribes one, and the law prescribes none for a cohabitation agreement. It is even valid orally. Written form is nonetheless strongly recommended, because after years of shared life the contributions and arrangements can hardly be proven otherwise.
What applies on separation if there is no agreement?
There is no matrimonial property law to fall back on. In BGE 108 II 204 the Federal Supreme Court rejected applying matrimonial property rules by analogy and held that whether the rules on the simple partnership apply must be decided on the specific circumstances. Where both partners worked together towards an economic result, BGE 109 II 228 applies the liquidation provisions of the simple partnership.
Why is Art. 533 para. 1 OR the biggest financial risk?
Because in the absence of an agreement it gives each partner an equal share in profit and loss — expressly irrespective of the nature and size of their contribution. Someone who financed 80 per cent of a joint acquisition can end up with 50 per cent. A contract may depart from this rule and align the quotas with the actual contributions.
What should a cohabitation agreement cover?
An inventory of the assets each partner brought in, the allocation key for rent, household costs and insurance, ownership of joint purchases, co-ownership shares and buy-out rights in a shared property, loans between the partners, compensation for reduced employment due to childcare, powers of attorney for illness, and the procedure on separation.
What can a cohabitation agreement not do?
It cannot create inheritance rights — that requires a will or a contract of succession. It cannot create entitlements under occupational pension law, cannot restrict child maintenance to the detriment of the child, and cannot produce the effects of a civil status. AHV survivors' pensions remain excluded because the AHVG links them exclusively to marriage.
Does my partner inherit if we have a cohabitation agreement?
No. Cohabiting partners are not statutory heirs, and the agreement does not change that — only a will or a contract of succession has effect under inheritance law. Since the succession law reform of 1 January 2023 the scope is wider: the compulsory portion of descendants is now half of the statutory entitlement instead of three quarters, and the parents' compulsory portion has been abolished.
Is a will enough to name my partner as a pension fund beneficiary?
No. In BGE 142 V 233 the Federal Supreme Court held that appointing a partner as heir in a will does not show an intention to designate a beneficiary under occupational pension law — not even where the partner is appointed sole heir. An express reference to the relevant pension fund regulations, or at least to occupational pension provision, is required. Submit the declaration of beneficiary that your fund asks for.
What protects the partner who reduces work for childcare?
Nothing, unless it is agreed. Cohabiting partners owe each other no maintenance, and there is no equalisation of assets. Whoever earns less, saves less and pays less into occupational pension provision over several years bears that disadvantage alone. A contractual compensation clause is therefore the single most important part of the agreement.
Is a template from the internet sufficient?
As a checklist a template is useful; as a contract it rarely is. The economically decisive part of a cohabitation agreement consists of figures — contribution quotas, valuation rules, compensation amounts — and no template knows them. A template also covers only one of four documents and leaves the parts that require a statutory form unresolved.
Can we amend the agreement later?
Yes, at any time and by mutual consent. Because the law prescribes no form for a cohabitation agreement, amendments are equally free of form. Record and date them in writing nonetheless. A review is advisable when a child is born, when property is purchased, when one partner reduces their workload and when you move to another country.