Buying Property as an Unmarried Couple in French-Speaking Switzerland: Legal Precautions to Take Before Signing

Buying an apartment or house together without being married is now a common reality in French-speaking Switzerland. Whether in Lausanne, Vevey, or the Vaud Riviera, couples living together outside of marriage represent a growing share of buyers. Yet, unlike married spouses whose financial situation is governed by the Swiss Civil Code, unmarried partners have virtually no automatic legal protection. Everything must be anticipated, drafted, and signed.

This absence of a legal safety net is not inevitable. It simply calls for thinking ahead about questions that the excitement of buying often tempts people to put off until the day they become urgent and painful. Here is an overview of the essential precautions to take.

Ordinary Co-ownership or Fractional Co-ownership: Choosing the Right Structure

When two unmarried people acquire real estate together in Switzerland, the land registry generally registers them as ordinary co-owners (Art. 646 CC). Each person holds a share, expressed as a fraction (1/2 each, or 1/3 and 2/3, etc.) that can freely reflect each party's actual financial contribution. This is the most common and simplest structure to put in place.

There is also joint ownership, linked to a simple partnership (Art. 530 CO). In this case, both partners hold the property together without individualized shares. This structure is more restrictive because it requires a joint decision for any act of disposal, including in the event of separation. For an unmarried couple, ordinary co-ownership with well-calibrated shares generally remains the most flexible and transparent option.

The land registry entry must accurately reflect who contributed what. If one partner financed 70% of the purchase price using their own funds (inheritance, personal savings, early withdrawal from the second pillar pension), registering a 50/50 split will create a distortion that could work against them the day the couple separates. A Vaud notary can guide you on the exact wording to use.

The Co-ownership Agreement: The Cornerstone of Your Protection

The notarized purchase deed is not enough. It confirms your status as co-owners but does not govern the day-to-day management of the property or the terms of exit. That is precisely the purpose of the co-ownership agreement, sometimes called a co-ownership convention. This private document, ideally drafted in authenticated form or at minimum in writing, addresses all the situations that the law leaves undefined.

A well-drafted agreement covers at minimum the following points: who pays what (mortgage charges, maintenance, taxes), how decisions about the property are made, what happens if one partner wants to sell their share, how the property's value is determined if one partner buys out the other, and how much time each partner has to vacate the property in the event of separation. Without this document, these questions will be decided by a civil court, often at considerable time and expense.

It is advisable to include a mutual right of first refusal clause: before being able to sell their share to a third party, each co-owner must first offer the buyout to the other party on the same terms. This avoids finding yourself co-owning a property with a stranger if the relationship breaks down.

Financing: Anticipating Contribution Imbalances

Financing a real estate purchase as an unmarried couple raises practical questions that banks and notaries routinely ask. Each partner can use their second pillar (pension fund) and third pillar to build up the required equity, but these amounts belong individually to each person. It is therefore essential to document precisely the origin of every franc invested in the purchase, using clear bank statements.

If one partner contributes more, whether from an inheritance, a gift from parents, or savings accumulated before the relationship, that personal contribution must be formally recorded as such. A promissory note or an explicit mention in the co-ownership agreement prevents a one-sided contribution from being reclassified as a gift in the event of separation or during estate proceedings. In French-speaking Switzerland, notaries are familiar with these situations and can advise you on the appropriate wording.

Regarding the mortgage, Vaud banks generally treat both partners as joint and several co-debtors. This means each partner is liable for the entire debt, not just their proportional share. If one partner can no longer meet their share of the payments, the bank can pursue the other for the full amount. This joint liability deserves to be fully understood before signing the loan agreement.

Death and Inheritance: The Absence of Automatic Protection

This is probably the point that unmarried couples underestimate the most. Under Swiss law, an unmarried life partner is not a legal heir. If one partner dies, their share of the real estate automatically passes to their legal heirs, meaning their children, parents, or siblings, and never to the surviving partner unless a specific provision has been made. In the worst case, the surviving partner could be forced to sell their own home to compensate in-laws or siblings-in-law.

Two instruments exist to address this gap: a will and an inheritance agreement. A will allows each partner to designate the other as a legatee or heir to their share, within the limits of the statutory reserved shares owed to protected heirs. If one partner has children from a previous relationship, the margin for maneuver is narrower. An inheritance agreement, concluded before a notary, offers stronger security because it is binding on both parties. As soon as a real estate purchase is being considered, a consultation with a Vaud notary regarding testamentary provisions is strongly recommended.

It is also possible to take out a life insurance policy in favor of the surviving partner, the proceeds of which would allow them to buy out the share inherited by the deceased's family. This combined approach, testamentary provisions and insurance coverage, is often the most comprehensive solution for an unmarried couple who own property together.

Taxation: Two Taxpayers, One Property

From a Vaud tax perspective, each co-owner is taxed separately on their share of the property's imputed rental value and on their share of the deductible mortgage debt. Passive interest is deductible in proportion to the debt borne by each party. This is a notable difference compared to married couples, who are subject to joint taxation.

This separate taxation can be an advantage if one partner has a significantly lower income than the other, since tax progressivity then works favorably. On the other hand, it complicates administrative management: each partner must declare their share in their own tax return, and supporting documents (mortgage interest, maintenance costs) must be allocated in accordance with the shares registered in the land registry. In the event of discrepancies, the cantonal tax authority may request explanations.

Separation: Planning the Exit Before Moving In

Raising the question of separation before buying is not a sign of distrust toward your partner: it is simply good planning. In the event of a breakup, unmarried co-owners do not have access to the divorce mechanisms that allow courts to decide on the allocation of the family home. They are referred to the general law of co-ownership, which provides that any co-owner may request a partition at any time (Art. 650 CC). In practice, this can result in a forced auction sale if no amicable agreement is reached.

The co-ownership agreement must therefore provide for a clear exit procedure: notice period, method for valuing the property (appraisal by an independent expert, for example), buyout priority, and financing terms for the buyout. These clauses prevent the emotional pressure of a separation from leading to decisions made in haste, often to the detriment of one or both partners.

The Right Questions to Ask Before Signing

Before signing anything, an unmarried couple should be able to answer these fundamental questions: Who is contributing how much, and in what form (personal funds, gift, family loan)? Do the ownership shares accurately reflect these contributions? Has a co-ownership agreement been drafted and signed? Has each partner made testamentary provisions in favor of the other? Is joint mortgage liability fully understood and accepted by both parties? And how will decisions be made in the event of disagreement over major renovations or a resale?

These questions deserve an in-depth session with a Vaud notary, ideally before even making a purchase offer. The fees for this consultation represent a modest investment relative to the amounts at stake and the risks avoided. At Homewell, we regularly assist unmarried couples with their property acquisition projects on the Vaud Riviera and in Lausanne, and we can connect you with the right legal contacts from the very start of the process.