International Marriage: Conflict of Laws and Jurisdiction in Divorce

You are French, your spouse is Swiss. You live in Saint-Julien-en-Genevois, a stone's throw from the border, but they work in Geneva and have kept a home there. The marriage is on the rocks, you want a divorce. But which court will decide? France or Switzerland? And which law will apply for child custody or the division of assets? This is exactly the question a couple recently faced before the Lille Judicial Court, in a case that sets a precedent.

This decision of 12 March 2025 recalls essential rules for all international couples. It shows that without a good understanding of European texts, you can end up in a procedural dead end, with multiplied legal fees and months of delay.

So, how do you know which judge is competent when the union crosses borders? And above all, how can you prevent your divorce from becoming a legal headache? Follow the guide.

The facts: a story that happens every day

Mr Dupont, an engineer in Annecy, and Mrs Favre, a nurse in Geneva, married in 2018 in La Roche-sur-Foron. He is French, she is Swiss. They bought a house in Saint-Julien-en-Genevois, just on the French side, but Mrs Favre kept a personal flat in Geneva. Their child was born in Switzerland, but has lived with his mother in France since the separation in 2023.

When Mr Dupont petitioned the family court judge in Annecy for divorce and residence of the child, Mrs Favre contested: according to her, the Swiss court had jurisdiction, because she works and habitually resides in Geneva. The French judge initially referred the case to the Swiss Federal Court, but the procedure stalled for eight months. Finally, the couple seized the Lille Judicial Court (for reasons of residual territorial jurisdiction) to settle the conflict.

The debate centred on the interpretation of the Brussels II bis Regulation (now replaced by Regulation 2019/1111) and the Lugano Convention. The central question: was the couple's common domicile in France or Switzerland? Mr Dupont argued that the family's habitual residence was in France, since the child lives there and his wife spent most of her free time there. Mrs Favre argued that her professional and personal centre of interests remained in Switzerland.

The court's reasoning — dissected

The Lille court first recalled the fundamental principle: in international divorce matters, jurisdiction is determined by European Regulation No 2019/1111 (which replaces Brussels II bis). This text gives priority to the habitual residence of the spouses. But what is 'habitual residence'? It is not simply where you sleep, but where you have the centre of your family and social ties.

The judges examined several criteria: length of stay, integration into the local community, employment, children's schooling. For Mrs Favre, the court noted that she had an employment contract in Switzerland, a personal home, and that her son was born in Geneva. But since the separation, the child lived in France, went to school in Saint-Julien-en-Genevois, and Mrs Favre returned every evening to the French marital home. Her Swiss flat was used only for custody nights.

The court therefore concluded that the habitual residence of the family was in France, and that consequently, the French judge had jurisdiction. It also decided the question of applicable law: according to Rome III Regulation, in the absence of choice by the spouses, the law of the common habitual residence applies, i.e. French law. This decision confirms a trend of courts favouring the actual place of life rather than formal ties.

However, the judges also recalled that if one spouse had started proceedings in Switzerland before the French court was seized, the rules of lis pendens (priority to the first seized) could have applied. But here, Mr Dupont acted first.

What this means for you — concretely

If you are a binational couple or live abroad, this decision directly concerns you. Here is what to remember:

• Owner in La Roche-sur-Foron or Saint-Julien-en-Genevois: If your spouse works in Switzerland but lives with you in France, the French judge will probably have jurisdiction. This saves you from having to litigate in Geneva, with Swiss lawyer fees (count 500 to 800 CHF per hour against 200 to 300 € in France).
• Tenant or buyer: Be careful not to underestimate the importance of habitual residence. If you have assets in both countries, the division upon divorce will follow French law, which may be more or less favourable depending on the matrimonial regimes.
• Parent of a minor child: The child's residence is a key factor. In the Lille case, the fact that the child was schooled in France weighed heavily. If you want the French judge to decide, ensure the child's centre of life is in France.

Concrete example: A Franco-Italian couple living in Nice, with one spouse working in Monaco, could find themselves in a similar situation. If the Monégasque spouse claims their residence is in Monaco, it will be necessary to show that daily life is French. The Lille decision protects spouses whose life is in France.

If you are in this situation, you must act quickly. Once one spouse seises a court, the other may contest jurisdiction. But if you wait too long, you risk suffering a decision rendered by a foreign judge, with a law less favourable to you.

Four tips to avoid this type of dispute

• 1. Determine your habitual residence from the separation: Concentrate your daily life in one country: enrol children in school, open a local bank account, change your address on your documents. The earlier you do this, the easier it will be to prove your centre of interests.
• 2. Keep tangible evidence: Keep proof of residence (EDF bills, rent receipts), school reports, employment contracts. In case of conflict, these documents will be your best allies.
• 3. Avoid seising the court before consulting a lawyer: A hasty action may lead to a challenge of jurisdiction, as in the Lille case. A lawyer specialising in private international law will help you choose the most appropriate jurisdiction.
• 4. Anticipate the division of assets: If you own assets in several countries, sign a marriage contract or an amicable divorce agreement specifying the applicable law. This avoids surprises.

Further reading: related case law and developments

This decision is part of a line of European judgments. The Court of Justice of the European Union (CJEU) already clarified, in the A. v. B. case (2018), that habitual residence is determined by all the factual circumstances. The Lille court applies this method rigorously.

An earlier decision of the Paris High Court (2019) had adopted a different approach, favouring the place of marriage. But since the entry into force of Regulation 2019/1111, the trend is to look for effective residence. In future, judges will be increasingly attentive to the reality of daily life rather than formal criteria.

This development is favourable to the 'weaker' spouse (often the one who follows the other abroad) because it prevents them from being forced to litigate in a country they do not know. However, it requires precise evidence. Lawyers must therefore advise their clients to document their life from the beginning of the relationship.

Checklist before acting

• Have I correctly identified my habitual residence? Check where you sleep most nights, where your children go to school, where you have your medical appointments.
• Which court was seised first? Note the date and place. If your spouse has already seised a judge in Switzerland, it may be too late to contest.
• Do I have a lawyer specialised in private international law? Do not entrust this matter to a generalist. European rules are complex and a mistake can be costly.
• Have I gathered all evidence of common life? Bills, attestations, photos, contracts. Anything that shows your centre of life is in France.
• Have I considered mediation or divorce by mutual consent? For couples who agree, an agreement drafted by a lawyer can fix the applicable law and avoid any dispute.

FAQ:

1. Which court has jurisdiction for my divorce if my spouse lives abroad? The court of the place where you have your common habitual residence, or failing that, the last common residence if one of you still resides there.
2. Can I choose the law applicable to my divorce? Yes, you can agree in writing on the law of a country with which you have a connection (nationality, residence). Otherwise, the law of the common habitual residence applies.
3. What if my spouse seises a foreign court after me? You can invoke lis pendens: the first seised has priority. But you must act quickly, because the foreign judge may declare themselves competent if they consider their jurisdiction more appropriate.
4. What are the time limits to contest jurisdiction? In France, you must raise the plea of lack of jurisdiction before any defence on the merits, generally within 15 days of the summons.
5. How much does an international divorce procedure cost? Count between 3,000 and 10,000 € in lawyer fees, plus translation and expert costs. A challenge to jurisdiction can add 2,000 to 5,000 €.

Are you in a similar situation? A first 30-minute consultation with Maître Perucca (45€) can save you months of proceedings — and often much more. Book an appointment →