Prenuptial agreements and matrimonial regimes for international couples

Many Franco-American couples do not know which matrimonial regime governs their marriage. They married in one country, moved to another, bought a flat in a third, and assumed that whatever they had signed, or not signed, on their wedding day still applied. Often it does not. The regime that determines who owns what in a marriage can change with a move, without anyone signing anything, and the couple discovers it at the worst possible moment: at a divorce, a death, or the sale of a property.

Olivia Uzan advises couples before marriage, during marriage and at its end, on the rules that govern their property in France and on how those rules interact with American law.

What a matrimonial regime is

Every married couple has one. In France, spouses who marry without a contract are under the regime of community of acquisitions: everything earned or acquired during the marriage belongs to both, everything owned before the marriage or received by gift or inheritance remains separate. Spouses who want something different sign a marriage contract before a notaire, before the wedding. The most common alternative is separation of property, under which each spouse owns what is in their name and nothing is shared. Other regimes exist, from the fully shared to the hybrid, and the choice can be tailored.

The regime governs the marriage, not just the divorce. It determines who can sell the family home, who is liable for a spouse’s debts, what happens on death, and how the estate passes to the children.

The French contract and the American prenup are not the same thing

An American prenuptial agreement typically does two things: it says how property will be divided if the marriage ends, and it limits or waives spousal support. A French marriage contract does the first, through the choice of regime, but not the second. Under French law, the prestation compensatoire, the compensation payment that may be due on divorce, cannot be waived in advance: an agreement to that effect signed before or during the marriage is void, and the question can only be settled once divorce proceedings have begun.

What happens when an American prenup with a support waiver comes before a French court is more nuanced. The provisions on property will generally be respected. The waiver of support will be examined, not simply ignored. The court asks whether the concrete result of applying it would be manifestly contrary to fundamental principles of French law. A blanket waiver that leaves one spouse with nothing after a long marriage is likely to be set aside; a balanced agreement between two spouses of comparable means has a better chance of being upheld. The outcome depends on the facts, and on how the agreement was drafted.

The reverse also needs attention. A French contract of separation of property is usually honoured by American courts as a premarital agreement, but only if it meets the requirements of the state concerned, which in California include full financial disclosure and, in practice, independent advice for each spouse. A contract signed in a notaire’s office in Paris in twenty minutes, in French, by a spouse who did not read it, may not survive a challenge in Los Angeles.

For a couple with a foot in each country, the answer is usually not to choose one document over the other but to make sure the two are consistent and that each has been drawn up with the other jurisdiction in mind.

Married abroad, living in France

For a couple married outside France, the first question is which country’s law governs their property. For marriages celebrated since 29 January 2019, European rules apply in France: in the absence of a choice, the regime is that of the country where the spouses first lived together after the wedding, and it does not change afterwards, however often the couple moves.

For earlier marriages the rules are different, and less forgiving. Under the convention then in force, a couple’s regime could change automatically, without any document being signed: after ten years’ residence in a new country, or immediately on settling in the country of their common nationality. The change is not retroactive. It applies to property acquired from that moment on, so that a couple can find themselves under two regimes at once, one for what they owned before, another for what came after. A couple married in New York in 2005 who moved to Paris in 2008, without a marriage contract and without choosing a governing law, have been under French community of acquisitions since 2018 for everything acquired since then, whatever they believe.

Working this out is not an academic exercise. It determines whether a Paris apartment bought in one spouse’s name belongs to that spouse alone or to both.

Choosing, and changing, the applicable law

Spouses can choose the law that governs their property, by agreement, either before or during the marriage, within limits: the law of a country where one of them lives or of which one of them is a national. A couple can also change their regime during the marriage, by a deed signed before a notaire. The two-year waiting period that used to apply was abolished in 2019, and court approval is no longer required simply because there are minor children. This is a useful tool for couples who married without thinking about it, who have moved countries, or whose circumstances have changed since the wedding.

When to seek advice

Before the wedding is the obvious moment. Before a move to another country is the next, and it is the one most couples miss. Before buying property together, before one spouse starts a business, before an inheritance: each of these is a point at which the regime matters and at which it can still be adjusted without conflict.

Advice at that stage is inexpensive. The same questions, raised for the first time in a divorce or an estate, are not.