International couples: marriage, property regime, children, inheritance

Marrying abroad or marrying a foreigner is easy; having the marriage recognised at home, choosing the law that governs your property, protecting the children and settling an estate spread over two countries is much less so. The common rules, and the Hague Conventions explained.

Marrying abroad, or marrying someone from another country

A marriage celebrated in a country according to that country's forms is in principle valid everywhere: it is the oldest rule of private international law. What varies is what each country demands of its own nationals before and after the ceremony. Almost all ask for the same things, under different names.

Three traps recur. Polygamy: in countries where it is allowed, check that your future spouse is not already married, because a second marriage is void in monogamous countries, even if celebrated at home. Religion: several countries forbid a Muslim woman from marrying a non-Muslim, which in practice requires a prior conversion — Morocco and Egypt provide for it, Tunisia dropped the rule in 2017 — failing which the marriage is not registered there and the couple is deemed to be cohabiting. Forced or sham marriage: most countries allow the deceived spouse to seek annulment, and refuse a residence permit or nationality when there was no real intention to marry.

Finally, marriage never has an automatic effect on nationality or on the right to reside. Both are obtained by a separate application, after a period of marriage and shared life ranging from two to five years depending on the country, with conditions on income, housing and often language. The details for each country are in the civil marriage pages.

Which law governs the couple's property?

A couple of two nationalities, or settled outside its home country, falls under a matrimonial property regime it often did not choose and discovers at divorce or death. The principle, almost everywhere: the spouses may choose the applicable law, among those of the nationality or habitual residence of either of them, by marriage contract; absent a choice, the law of their first common habitual residence after the marriage applies — not that of the place of the ceremony.

In the European Union, Regulation (EU) 2016/1103 sets these rules for marriages celebrated since 29 January 2019 in the participating states — France, Belgium, Luxembourg, Germany, Austria, Italy, Spain, the Netherlands and a dozen others —, with an important novelty: the law so determined no longer changes by itself. For marriages celebrated between 1 September 1992 and 28 January 2019, France, Luxembourg and the Netherlands still apply the Hague Convention of 14 March 1978, which provides for an automatic change of law in three cases: when the spouses settle in a state of which both are nationals, when they have lived for more than ten years in the same state, or when they settle in the state of their residence at the time of the marriage. Couples married in the 2000s have thus changed regime without knowing it. Outside these texts, each country has its own rule — Switzerland uses the common domicile, Quebec the first residence, the United Kingdom has no matrimonial regime at all and lets the judge divide.

The advice is the same everywhere: a marriage contract, even a short one, naming the law and the regime, beats the default rule; and it can be made or changed after the marriage.

The children of an international couple

Parentage and name. The child generally has the nationality of each parent when their countries pass nationality by descent, and sometimes that of the country of birth: dual nationality is the normal situation of these children. The surname follows the law of the child's nationality or of the country of the birth record depending on the country, which produces different names from one passport to another; in the European Union, a name validly given in one state must be recognised in the others. Register the birth with the consulate of each country.

Parental responsibility and residence. The competent judge is that of the child's habitual residence, and most often applies his own law: that is the rule of the 1996 Hague Convention and, in the Union, of the "Brussels IIb" regulation. A parent who takes the child to another country without the written agreement of the other or of a judge commits an abduction within the meaning of the 1980 Hague Convention: more than a hundred states order the child's return, often within weeks, without examining custody. Before any move abroad, the agreement or the judgment — no exception. The page on custody and maintenance details the remedies, including travel bans.

Child maintenance fixed in one country is recovered in another thanks to the 2007 Hague Convention and, in the Union, to a dedicated regulation, through central authorities: slow, but effective. Intercountry adoption is governed by the 1993 Hague Convention, which requires approval in the receiving country and forbids any profit: see the adoption page.

International inheritance

An estate is international as soon as something links it to another country: assets abroad, a nationality or residence of the deceased different from that of the heirs. The question is then: which law says who inherits, and how much? In the European Union, Regulation (EU) 650/2012 has applied since 17 August 2015 a single law to the whole estate — that of the deceased's last habitual residence — unless he chose, by will, the law of his nationality; it also creates a European certificate of succession recognised in all participating states (Denmark and Ireland are outside the system). Outside the Union, many countries — the United Kingdom, the United States, Canada — apply the law of the place where real property is located to that property and the law of the domicile to the rest, which "splits" the estate and can bring contradictory laws into play.

The stakes are concrete: civil-law countries reserve a share for the children (forced heirship), common-law countries let everything be left freely, and the surviving spouse's share ranges from everything to nothing. A will that designates the applicable law, drawn up in a form recognised everywhere — the 1961 Hague Convention on the form of wills sees to that —, is the only way to know in advance. An old piece of advice still holds: the spouse who settles abroad keeps an account and, if possible, assets in the home country. Details are on the inheritance and gifts between spouses and inheritance pages.

The Hague Conventions, explained

The Hague Conference on Private International Law is the organisation that has negotiated, since 1893, the treaties by which countries agree on which court has jurisdiction, which law applies and how each recognises the others' decisions. Seven of its conventions directly concern an international couple.

ConventionWhat it doesWhat it changes for you
Apostille (5 October 1961) — over 120 states Replaces the chain legalisation of public documents by a single stamp, the apostille, affixed by the state of origin. Your birth and marriage certificates, judgments and diplomas are accepted abroad with an apostille; between EU states, a 2019 regulation even dispenses civil status documents from the apostille, with multilingual forms.
Form of wills (5 October 1961) A will is formally valid if it complies with the law of the place where it was made, or of the testator's nationality, domicile or residence. A will drawn up at home is not void abroad on a question of form.
Matrimonial property regimes (14 March 1978) — France, Luxembourg, Netherlands Sets the law applicable to the spouses' property: limited choice, otherwise first common residence; automatic change in some cases. Still governs couples married between 1992 and January 2019 in those three countries; since replaced by EU Regulation 2016/1103.
Celebration and recognition of marriages (14 March 1978) — Australia, Luxembourg, Netherlands A marriage valid in the state of celebration is recognised in the other contracting states. Few countries have ratified it; recognition most often rests on national law and registration.
International child abduction (25 October 1980) — over 100 states Organises the prompt return of a child wrongfully removed or retained to the country of habitual residence, through central authorities. Leaving with the child without agreement triggers a return procedure; conversely, it is the remedy of the parent left behind.
Intercountry adoption (29 May 1993) — over 100 states Frames adoption between countries: central authorities, approval of adopters, free consent of birth parents, ban on profit. An adoption made under the convention is recognised by operation of law in the other contracting states.
Protection of children (19 October 1996) — some fifty states Gives jurisdiction to the judge of the child's habitual residence for parental responsibility, custody and protection, and has his decisions recognised. A custody judgment given in a contracting state is recognised in the others without a new trial.
Recovery of maintenance (23 November 2007) — European Union, United States, Brazil, Turkey, Ukraine… Allows child or spousal maintenance to be enforced abroad, through central authorities, free of charge for the creditor in most cases. A debtor who has moved abroad does not escape maintenance, but count in months.

The lists of contracting states change: they are kept up to date on the website of the Hague Conference (hcch.net). The dates given are those of signature.

The law country by country

The exact formalities — who issues the capacity certificate, where to register, how long before nationality — are specific to each country. They are in the country pages on civil marriage, property regimes and inheritance.

Page checked in September 2026. The data cited can change.

Locate this page in the site map

A question, a correction, a suggestion? Write to us.