Buying real estate as cohabiting partners in Switzerland: full details
- Cohabitation in Switzerland: the legal position
- Which form of ownership should cohabiting partners choose?
- Mortgage: what the bank looks at and what couples often overlook
- Taxation: differences in equity contributions can matter more than the rate
- Three scenarios for a CHF 900’000.– house
- Analyse the risks before signing, not afterwards
- FAQ: buying property as cohabiting partners in Switzerland
Buying property as cohabiting partners involves more than sharing the equity contribution and monthly payments. In Switzerland, four separate realities can diverge: the person entered in the land register, the person contributing the equity, the person signing the mortgage debt and the person who actually bears the costs. These differences become visible on separation, death, a fall in income or refinancing.
For this reason, buying a house as cohabiting partners requires ownership, debt, equity, taxation and exit arrangements to be structured before comparing rates. A poor setup can make the home impossible to keep after a separation.
Cohabitation in Switzerland: the legal position in 2026
No automatic federal status, but a PACS is being prepared
Cohabitation in Switzerland means living as a couple without being married. Unlike marriage, it does not automatically create a matrimonial property regime, a general duty of maintenance between partners or a statutory inheritance right for the survivor. The length of the relationship does not, by itself, create a form of “common-law marriage” applicable to the home.
One current development is worth knowing. On 27 May 2026, the Council of States Legal Affairs Committee opened consultation on a federal PACS project, presented as an “enhanced form of cohabitation”. The consultation period ended on 17 September 2026.
The triangle to check: owner, debtor and funder
To analyse a property purchase by cohabiting partners, ask three separate questions: who owns the property? Who owes the money to the bank? Who actually paid the equity contribution and the costs? The answer can differ for each question.
Example: A and B buy a house 50/50. A contributes CHF 150’000.– and B CHF 30’000.–, while both sign a jointly and severally liable mortgage. Ownership is 50/50, the equity contribution is 83/17 and each partner’s exposure to the bank may exceed 50%. Without an agreement, the CHF 120’000.– difference will eventually have to be characterised as a loan, claim, final contribution or gift.
When buying property as cohabiting partners, the principle to remember is simple: paying does not make you an owner. Financing renovations, an amortisation or equity on the other partner’s home does not automatically create an ownership share in the property.
Which form of ownership should cohabiting partners choose?
Co-ownership: the shares are visible, but they need to be chosen carefully
In most cases involving a property purchase by an unmarried couple, co-ownership is the clearest structure. Each person owns a share entered in the land register: 50/50, 60/40, 75/25, etc. These percentages may reflect the contributions, but nothing requires a couple to choose 50/50.
The classic trap is to register 50/50 “because we are a couple” even though the equity contributions are very unequal. When buying property as cohabiting partners, the ownership share should be compared with the equity contribution, the debt assumed between the partners, future amortisation and the intended allocation on resale. This should be decided before any purchase by cohabiting partners.
When buying property as cohabiting partners, changing the ownership shares later is not a simple administrative correction. Transferring a share requires a deed and an entry in the land register, with possible fees and cantonal tax consequences.
Joint ownership: legally possible, but pay close attention to the 2nd pillar
When buying property as cohabiting partners, joint ownership may arise in particular through a simple partnership. Unlike co-ownership, neither partner has a freely individualised share of the real estate; decisions depend on the rules governing the joint ownership arrangement.
For cohabiting partners buying property, joint ownership has a little-known feature: according to the Federal Social Insurance Office, an advance withdrawal from the 2nd pillar is permitted for sole ownership, co-ownership and joint ownership with a spouse or registered partner. An unmarried cohabiting partner should therefore check this structure before relying on a withdrawal under the home ownership promotion scheme. Co-ownership, by contrast, is among the permitted forms.
Sole ownership: a partner who pays acquires no automatic property rights
The situation becomes much more delicate when the second partner contributes CHF 50’000.– to the purchase, finances a new kitchen, contributes to amortisation or pays part of the interest. Without an appropriate document, that payment is not a hidden share in the house. To buy as cohabiting partners in this way, you should determine in advance whether these amounts are a loan, a contribution to housing costs, a repayable investment or a gift.
Mortgage: what the bank looks at and what couples often overlook
Joint and several liability: 50% ownership can mean 100% liability to the bank
When two incomes are needed for a property purchase by cohabiting partners, the lender often requires both partners to be liable. With joint and several liability, the bank is not limited by the private arrangement that “each pays half”.
A property purchase by cohabiting partners can therefore be 50/50 in the land register without being 50/50 in terms of liability to the bank. A cohabitation agreement can provide for recourse between the partners, but it does not restrict the lender’s rights.
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This distinction becomes decisive on separation. If A buys out B’s share, B does not automatically disappear from the loan. The bank must agree to release B and reassess A’s affordability on a standalone basis. A property purchase by cohabiting partners should therefore be tested using only one income before signing.
CHF 900’000.– does not always mean CHF 180’000.– of equity
For this property purchase by cohabiting partners, CHF 900’000.– with an 80% mortgage appears to require CHF 180’000.– of equity. But if the bank uses a mortgage lending value of CHF 850’000.–, 80% is CHF 680’000.–: CHF 220’000.– of equity is then required.
This CHF 40’000.– difference from the original plan can cause a house purchase by cohabiting partners to fail at the last minute. It is even more significant if both partners had planned to draw almost all of their contribution from occupational pension assets.
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For affordability, lenders often use a theoretical interest rate close to 5%, with amortisation and maintenance costs added. When buying property as cohabiting partners, comparing several lenders therefore also means comparing their valuation and affordability methods, not just their advertised rate.
Taxation: differences in contributions can matter more than the mortgage rate
Before 2029: ownership share, debt and actual payment are not always the same thing
For a property purchase by cohabiting partners, each partner remains taxed separately. Tax value, imputed rental value and property expenses generally follow the ownership shares under cantonal practice; debt and interest must instead be aligned with debtor status and internal agreements.
When buying property as cohabiting partners, a non-owner partner may, in certain arrangements, deduct the interest they actually bear if they are themselves jointly and severally liable as a co-debtor. Simply paying an invoice that is legally owed by the other partner does not always create a personal deduction.
For cohabitation and property ownership, the mortgage contract, internal agreement and actual bank payments should therefore remain consistent. Tax authorities may ask why someone declaring 50% of the property bears 80% of the debt, or why a person with no ownership claims an interest deduction.
Unequal contributions raise another question. If A contributes much more than their ownership share justifies, the excess may, depending on the structure and canton, be treated as a loan or a gift. When buying property as cohabiting partners, it is better to characterise this difference at the outset than to discover it during a tax audit or separation.
From 1 January 2029: the tax logic of financing changes
For property purchases by cohabiting partners, the reform of owner-occupied property taxation will enter into force on 1 January 2029. The imputed rental value of owner-occupied homes will be abolished. In return, the deduction of debt interest relating to owner-occupied housing will be heavily restricted, and maintenance costs will no longer be deductible as they are today.
A temporary deduction will remain for the first purchase of a main residence. Official documents provide for an initial maximum of CHF 10’000.– for a married couple and CHF 5’000.– for a single taxpayer, for ten years with a 10% reduction each year. For a property purchase by cohabiting partners, the conditions will need to be examined separately for each taxpayer.
This reform changes the analysis of a highly leveraged property purchase by cohabiting partners. Keeping a large mortgage solely to obtain a tax deduction will become far less relevant for an owner-occupied home. A mortgage broker will therefore need to compare not only current products, but also the amortisation strategy up to 2029 and beyond.
Three scenarios for a CHF 900’000.– house
To illustrate a property purchase by cohabiting partners, the three scenarios assume a purchase price and mortgage lending value of CHF 900’000.–, CHF 180’000.– of equity and a CHF 720’000.– mortgage. At 2%, annual interest is CHF 14’400.–. Cantonal acquisition costs are treated separately.
Scenario A: purchase in 50/50 co-ownership
| Item | Cohabiting partner A | Cohabiting partner B |
|---|---|---|
| Ownership share | 50% = CHF 450’000.– | 50% = CHF 450’000.– |
| Equity | CHF 90’000.– | CHF 90’000.– |
| Internal mortgage debt | CHF 360’000.– | CHF 360’000.– |
| Annual interest at 2% | CHF 7’200.– | CHF 7’200.– |
| Current tax deduction | Share corresponding to their debt and the applicable cantonal rules | Share corresponding to their debt and the applicable cantonal rules |
| Acquisition costs | Paid according to the couple’s agreement; their allocation does not automatically change the registered ownership shares. | |
| Point to watch | With joint and several liability to the bank, the partners’ internal 50/50 economic split does not necessarily limit the bank’s claim. | |
Scenario B: purchase in joint ownership
| Item | Couple’s situation |
|---|---|
| Ownership | Property held jointly, for example through a simple partnership; there is no freely individualised share as there is with co-ownership. |
| Equity | CHF 180’000.– in total according to the internal agreement. |
| Mortgage | CHF 720’000.–, generally with both partners liable if both incomes are needed. |
| Annual interest at 2% | CHF 14’400.– in total; the tax allocation should be documented according to the internal rights and the debt. |
| Possible tax deduction | Allocated according to the tax and contractual position; not simply according to who makes the bank transfer. |
| Specific costs | A simple partnership agreement, legal advice and exit arrangements should be planned in addition to the usual acquisition costs. |
| Point to watch | Under the home ownership promotion rules, an advance withdrawal from the 2nd pillar for joint ownership is not provided for two unmarried cohabiting partners. |
Joint ownership may suit certain joint projects, but it should not be chosen simply because its name sounds more “couple-like”. For cohabiting partners buying a house, co-ownership is often more compatible with tracing contributions and using pension assets individually.
Scenario C: sole ownership
| Item | Cohabiting partner A, owner | Cohabiting partner B, non-owner |
|---|---|---|
| Ownership share | 100% = CHF 900’000.– | 0% |
| Equity | CHF 180’000.– | CHF 0.–, unless separately documented financing is provided |
| Mortgage | CHF 720’000.– | None in this scenario |
| Annual interest at 2% | CHF 14’400.– | CHF 0.– legally owed to the bank |
| Current tax deduction | For A under the applicable rules | No mortgage-interest deduction if B is not a debtor |
| Acquisition costs | Legally borne in accordance with the deed and the arrangements made | A financial contribution does not automatically confer ownership |
| Point to watch | If B finances CHF 50’000.– of works or amortisation, the treatment of that amount should be recorded in writing. | |
Analyse the risks before signing, not afterwards
Separation: test the buyout before you even buy
A serious risk analysis of a property purchase by cohabiting partners involves assuming that the couple separates twelve months after receiving the keys. Who buys out the other’s share? At what value? Within what timeframe? And, above all, can that person take over the mortgage alone?
Buying out the property share and releasing a co-debtor are two different transactions. Even if A and B agree that A will keep the house, the bank may refuse to release B if A’s income does not meet its affordability criteria. A private agreement cannot impose this change on the lender. A property purchase by cohabiting partners should therefore also be tested using each partner’s income separately.
You should also plan for what happens to a fixed-rate mortgage. A sale or refinancing before maturity may trigger an early-exit charge. The cohabitation agreement can specify who bears this cost, how the house is valued and how long one partner has to finance the buyout before a sale to a third party is triggered.
Death: half of the home does not automatically pass to the survivor
The surviving cohabiting partner is not automatically the statutory heir to the deceased partner’s property share. For a property purchase by cohabiting partners, a will or, depending on the family situation, an inheritance agreement should therefore be coordinated with the mortgage.
The real issue is often liquidity. Receiving more rights over the house is not enough if the survivor must compensate other heirs or take over alone a debt that was calculated on two incomes. Life insurance can provide the capital needed to reduce the mortgage or buy out inheritance rights. The beneficiary clause of the 3rd pillar must be checked separately: it is not replaced by a will.
Costs, questions and protective measures
There is no single nationwide tariff for securing a property purchase by cohabiting partners. Notary fees, land-register charges, property-transfer tax and creation of the mortgage security vary by canton. For initial planning only, an allowance of 2% to 5% of the price is sometimes used, i.e. CHF 18’000.– to CHF 45’000.– on CHF 900’000.–; it should then be replaced by a precise cantonal calculation.
Possible additional items include a cohabitation agreement, a will, an inheritance agreement, tax advice and death insurance. Before requesting mortgage offers, the couple should know whether the ownership shares match the equity contributions, who can keep the home on one income, how the house will be valued for a buyout and whether the 2nd pillar is compatible with the ownership structure.
| Risk | Possible consequence | Measure to put in place |
|---|---|---|
| Unequal contribution not documented | Dispute or possible tax treatment as a gift | Adjusted ownership share or written loan |
| Both incomes essential | Unable to take over the mortgage alone | Individual affordability test |
| Long-term fixed-rate mortgage | Charge on an early sale | Allocation rule and maturity structure |
| Death of a co-owner | Heirs enter the property ownership structure | Coordinate inheritance and insurance |
| Joint ownership + home ownership promotion | 2nd-pillar funds cannot be used as planned | Confirm with the pension fund before signing the deed |
This preparation changes the discussion with your mortgage broker. For a property purchase by cohabiting partners, the issue is no longer simply comparing the rate, but also the mortgage lending value used, how both incomes are taken into account, amortisation flexibility and the terms of a future debt takeover.
FAQ: buying property as cohabiting partners in Switzerland
Can we buy 50/50 with different equity contributions?
Yes. The difference should, however, be characterised: a loan between partners, a final contribution or another agreed mechanism. Leaving a significant difference undocumented is an unnecessary weakness in a property purchase by cohabiting partners.
If we own 50/50, can the bank demand only 50% from each of us?
No. Ownership shares and debt are two separate legal relationships. With joint and several liability, the bank’s rights are those set out in the mortgage contract, not the couple’s internal split.
Does joint ownership allow us to use both of our 2nd pillars?
Particular care is needed. The home ownership promotion rules provide for joint ownership with a spouse or registered partner. For two cohabiting partners, co-ownership is the structure to examine when each wants to use occupational pension assets.
What happens if one partner wants to keep the house after a separation?
They must finance the buyout of the other partner’s share and obtain the lender’s consent to take over the debt alone. The bank may carry out the entire affordability test again.
Do we still need to account for imputed rental value when buying in 2026?
Yes. The current system remains applicable until the reform enters into force on 1 January 2029. A property purchase by cohabiting partners completed today should therefore be analysed under both systems.
A well-structured property purchase by cohabiting partners should remain understandable when the relationship, income or taxation changes. An assessment of borrowing capacity before the promise of sale makes it possible to test several allocations of debt and equity and then compare lenders on genuinely comparable terms. A professional mortgage broker in your region can carry out all these tasks for you.
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Official sources
– Federal Assembly, Council of States Legal Affairs Committee
– Federal Social Insurance Office, “Home ownership promotion using occupational pension assets”
– Federal Tax Administration, reform of owner-occupied property taxation,
Tax, inheritance, notarial and financing rules may vary depending on the canton, ownership structure, pension fund and lender’s contract. This guide provides general information and does not replace legal, tax, inheritance or mortgage advice tailored to your situation.
