Your Baby Was Born in France to British Parents After Brexit: Is Your Child French, British or Both, and How to Secure Both Passports

Your baby was born in a French maternité (maternity hospital). The acte de naissance (birth certificate) drawn up at the local mairie (town hall) is a French document, the health visitor speaks French, and your child will probably grow up on cantine lunches and dictées. So here is the question every British parent in France eventually asks, usually at passport-application time: is my French-born child French, British, or both? The short answer is that a baby born in France to two British parents is normally British at birth but not French at birth, and becomes French later through one of two well-marked legal routes. Nothing about Brexit changed those nationality rules, because nationality law never depended on European Union membership. What Brexit did change is the residence paperwork around your family, which makes it more important than ever to put your child’s status on a proper legal footing while the evidence is fresh. This guide explains, first, what nationality your child holds on the day of birth, and second, the exact procedures, documents and court challenges that turn a French-born British child into a dual Franco-British national holding both passports.

I. Is your French-born baby French at birth, and is that baby British?

A. Is a baby born in France to British parents automatically French at birth?

No. France does not grant its nationality to every child born on its soil. The basic rule of attribution by parentage is stated in one sentence: “Est français l’enfant dont l’un des parents au moins est français.” Where both parents are British and neither is French, that route is closed, and nothing in the birth registration alters the position. The mairie records the fact of birth and issues the acte de naissance, but it does not decide nationality. Many parents discover this distinction only years later, when a consulate or a préfecture (the state authority office for each département) asks for proof of nationality and the birth certificate alone is not accepted. Keep the two ideas separate from the start: registration of birth is automatic, attribution of French nationality is not.

The Code civil does provide safety nets for children who would otherwise have no nationality at all, and British parents should understand them even though they will rarely need them. A child born in France to unknown parents is French, under article 19 of the Code civil. More broadly, article 19-1 provides: “Est français : 1° L’enfant né en France de parents apatrides ; 2° L’enfant né en France de parents étrangers pour lequel les lois étrangères de nationalité ne permettent en aucune façon qu’il se voie transmettre la nationalité de l’un ou l’autre de ses parents.” Because British nationality law does transmit citizenship to a child born abroad to a British parent, as explained below, a baby with two British parents is not left stateless and does not fall into this safety net. Note the closing caution of the same article: “Toutefois, il sera réputé n’avoir jamais été français si, au cours de sa minorité, la nationalité étrangère acquise ou possédée par l’un de ses parents vient à lui être transmise.” Attribution at birth can therefore be revisited where the facts change during childhood.

There is one genuine exception that directly concerns some British families, known as double jus soli. Article 19-3 of the Code civil states: “Est français l’enfant né en France lorsque l’un de ses parents au moins y est lui-même né.” If one of you, the British parents, was yourself born in France, perhaps because your own parents were posted there, then your baby is French from birth even though you are both British citizens. This catches a surprising number of military, diplomatic and expatriate families, so check your own place of birth before assuming your child is British only. And where French nationality is attributed after birth on any of these bases, article 20 gives it retroactive effect: “L’enfant qui est français en vertu des dispositions du présent chapitre est réputé avoir été français dès sa naissance, même si l’existence des conditions requises par la loi pour l’attribution de la nationalité française n’est établie que postérieurement.” The child is then treated as having been French since day one, which simplifies everything from school administration to inheritance.

B. Is that same baby automatically British, and does British citizenship run out down the generations?

Normally yes, provided at least one of you is the right kind of British citizen. The British government’s own guidance states the principle that British citizenship normally passes down one generation to children born outside the United Kingdom (who can apply for citizenship through a British parent) In practice this means that if you were born in the United Kingdom, you are what British lawyers call British otherwise than by descent, and your baby born in France is automatically British at birth, though classified as British by descent. You do not need to register the birth with any British authority for the citizenship itself to exist, although you will want the paperwork, and you should apply for the child’s first British passport in good time through the usual overseas route. The same page adds the warning that matters for the next generation: But children born outside the United Kingdom to such a parent do not automatically become citizens themselves. That warning is aimed at your child, once grown up.

Understand the vocabulary, because it governs your grandchildren. A parent who is British otherwise than by descent, typically by birth in the United Kingdom, transmits citizenship automatically to children born anywhere in the world. A parent who is British by descent, typically because they were themselves born abroad to a British parent, does not automatically transmit citizenship to their own children born abroad. So if you were born in Manchester and your daughter is born in Lyon, she is automatically British. But if she later settles in Bordeaux and has children of her own there, those grandchildren are not automatically British at birth. They may still have a route: the government’s guidance confirms that Those who are not automatically citizens may be eligible to apply to register as citizens (the registration route). Registration is a formal application, with residence conditions and a fee, and it should be planned rather than assumed. Families that move abroad for good and stay abroad for generations can therefore lose the automatic thread, which is one more reason to secure French nationality for your French-born child as well: it gives the family a second permanent anchor that does not depend on counting generations of British births.

None of this was altered by Brexit. British citizenship by descent never depended on European Union law, and the Withdrawal Agreement says nothing about nationality. What Brexit changed is immigration status: you as parents now hold your right to live in France under the Withdrawal Agreement or under ordinary French immigration law, while your child born in France does not acquire a residence right from the place of birth. Do not confuse the two systems. Your baby can be fully British from birth and still need, in due course, the same careful residence paperwork as any foreign national child in France, until French nationality is acquired. That is why the second half of this guide matters practically as well as sentimentally: French nationality for your child is not only about identity and a second passport, it is the only status that settles residence, voting, public-sector access and freedom from immigration paperwork once and for all.

II. How do you actually make your French-born child French and hold both passports?

A. How do you claim French nationality for your child before the age of 18?

The early route is the déclaration de nationalité (nationality declaration) made during childhood, and it is the route most British parents should aim for, because it puts the matter beyond doubt years before adulthood. Article 21-11 of the Code civil organises it in these terms: “L’enfant mineur né en France de parents étrangers peut à partir de l’âge de seize ans réclamer la nationalité française par déclaration, dans les conditions prévues aux articles 26 et suivants si, au moment de sa déclaration, il a en France sa résidence et s’il a eu sa résidence habituelle en France pendant une période continue ou discontinue d’au moins cinq ans, depuis l’âge de onze ans. Dans les mêmes conditions, la nationalité française peut être réclamée, au nom de l’enfant mineur né en France de parents étrangers, à partir de l’âge de treize ans, la condition de résidence habituelle en France devant alors être remplie à partir de l’âge de huit ans.” Read that carefully, because it contains two tracks. From sixteen, the teenager claims nationality personally. From thirteen, the parents claim it on the child’s behalf, and the five-year residence clock then runs from the age of eight rather than eleven. The government’s guidance page for parents confirms the shape of the scheme in plain language (nationality of a child born in France to foreign parents): a child born in France to foreign parents can seek French nationality by declaration from the age of sixteen. Do not wait for eighteen if you can act at thirteen. An early declaration means your child enters sixth form, university applications and first jobs with French nationality already established, and it removes any argument later about gaps in residence during the late teenage years.

Two further points in the procedure deserve attention. First, the child’s own agreement is required: the Code provides, in article 21-11 itself, that “Le consentement du mineur est requis, sauf s’il est empêché d’exprimer sa volonté par une altération de ses facultés mentales ou corporelles”, a point the administration repeats in its guidance for parents (the child must indicate agreement). In practice the teenager signs, and parents of a thirteen-year-old should prepare the child for that formality rather than treating the file as purely parental paperwork. Second, the declaration is received by the greffe, the court clerk’s office, of the tribunal judiciaire (the ordinary civil and criminal court for the area), or by the consul where the family lives abroad. Article 26 of the Code civil states: “Les autres déclarations de nationalité sont reçues par le directeur des services de greffe judiciaires du tribunal judiciaire ou par le consul”, and adds the sentence that governs every file: “Il en est délivré récépissé après remise des pièces nécessaires à la preuve de leur recevabilité.” Insist on that récépissé (formal receipt): it proves the date of your declaration and starts the clock for any challenge if the administration later refuses to register it. Build the file as a litigator would, even though you hope never to litigate: full birth certificate of the child, proof of the parents’ nationality, and above all continuous proof of the child’s habitual residence in France, year by year, through school certificates (certificats de scolarité), medical records and any official correspondence. For parents pursuing their own French nationality in parallel, the adult route works differently and is explained in our guide to French naturalisation by decree for British adults, but the child’s declaration route described here stands on its own and does not depend on the parents becoming French.

If the declaration is refused registration, or simply left without an answer, you are not at the end of the road. The refusal can be contested before the tribunal judiciaire, and the decided cases show exactly where files succeed or fail: on evidence of real, continuous life in France. A useful illustration is the judgment of the Court of Cassation, First Civil Chamber, of 14 April 2010, appeal no. 08-21.312, published in the Bulletin, available at https://www.courdecassation.fr/decision/607956619ba5988459c492b7. The case concerned a declaration for a minor, and the Court approved the appeal judges’ reasoning that “il faut, pour bénéficier des dispositions de l’ancien article 21-12 du code civil que l’enfant soit effectivement recueilli et élevé en France”. The young applicant had been enrolled in a French school for years, but attendance had been patchy, with long unexplained absences, regular unproven stays abroad, and no supporting statements from people who had actually seen him living in France. The Court therefore confirmed that “elle a pu déduire de cet ensemble de circonstances souverainement appréciées que M. X… ne rapportait pas la preuve qu’il remplissait les conditions pour souscrire une déclaration de nationalité”, and it closed with “REJETTE le pourvoi.” The mechanism differs from article 21-11, but the evidential moral is identical and the courts apply the same rigour: enrolment on paper is not residence in fact. For your article 21-11 file, that means school attendance records rather than mere registration, medical and extracurricular traces of daily life, dated travel records showing that holidays abroad were only holidays, and, where possible, short written statements from teachers or family friends. Where the greffe refuses registration and you consider the file solid, instruct counsel to seize the court promptly rather than filing a second informal request that resets nothing.

B. What happens automatically at 18, and how do you prove French nationality with papers that consulates and prefectures accept?

If no declaration was made during childhood, French law still does the work at majority, provided the residence conditions are met. Article 21-7 of the Code civil provides: “Tout enfant né en France de parents étrangers acquiert la nationalité française à sa majorité si, à cette date, il a en France sa résidence et s’il a eu sa résidence habituelle en France pendant une période continue ou discontinue d’au moins cinq ans, depuis l’âge de onze ans.” Acquisition here is automatic, by operation of law, not by decision. No ceremony, no decree, no discretion: at midnight on the eighteenth birthday, the young adult who satisfies the residence test is French. The same article even imposes an information duty, providing that “Les tribunaux judiciaires, les collectivités territoriales, les organismes et services publics, et notamment les établissements d’enseignement sont tenus d’informer le public, et en particulier les personnes auxquelles s’applique le premier alinéa, des dispositions en vigueur en matière de nationalité.” In practice, do not rely on being informed. Parents should count the five years themselves, from eleven to eighteen, and keep the proof, because the administration will ask for it when the child applies for an identity card, a passport, or a first residence-free status as a young French adult. The official guidance confirms the practical consequence: a child born in France to foreign parents obtains French nationality at eighteen where the residence conditions are satisfied (official guidance on nationality at eighteen), and the young adult is then directed to request the certificate described below.

The leading cautionary tale on the residence test is a published judgment of the Court of Cassation, First Civil Chamber, of 10 July 2013, appeal no. 12-21.357, available at https://www.courdecassation.fr/decision/6079737a9ba5988459c49e20. A woman born in Reims to foreign parents claimed French nationality acquired at majority, arguing that years spent abroad as a child should count because her father worked for a French bank overseas. The Court rejected the argument, holding that “l’assimilation à la résidence en France, au sens de l’article 78 du code de la nationalité, ne bénéficiant qu’à l’étranger exerçant cette activité ou à son époux s’ils habitent ensemble”, so that the daughter herself “n’en avait pas bénéficié, de sorte qu’elle n’avait pas acquis la nationalité française de plein droit à sa majorité”, and it ended with “REJETTE le pourvoi.” Two lessons for British families follow. First, long childhood absences from France, even for perfectly respectable professional reasons, can break the five-year chain, so boarding school abroad, a posting outside France, or years shuttling between two homes must be counted honestly against the test. Second, assimilation of foreign residence to French residence is narrowly personal to the worker and, at most, the spouse living with them: it never flows down sideways to the children. If your child’s schooling history includes a gap, take advice before asserting automatic acquisition at eighteen, and consider the declaration route of article 21-11 instead, where the timing can be chosen and the file prepared.

Whether nationality comes through the childhood declaration or automatically at eighteen, there remains the question of proof, and here French law is strict but clear. The burden lies on the person claiming to be French: article 30 of the Code civil states that “La charge de la preuve, en matière de nationalité française, incombe à celui dont la nationalité est en cause.” The same article then gives the way out: “Toutefois, cette charge incombe à celui qui conteste la qualité de Français à un individu titulaire d’un certificat de nationalité française délivré conformément aux articles 31 et suivants .” Once your child holds the certificat de nationalité française, universally called the CNF, the burden flips, and it is for anyone disputing French nationality to prove their case. Only one authority can issue that document: article 31 provides that “Le directeur des services de greffe judiciaires du tribunal judiciaire a seul qualité pour délivrer un certificat de nationalité française à toute personne justifiant qu’elle a cette nationalité.” The application is filed at the tribunal judiciaire of the child’s home, with the official form and supporting documents, and the administration’s own guide explains that the originals of the documents must be produced when filing at the court or whenever the clerk’s office summons you during examination. For families in Paris and the Île-de-France, that means the nationality desk of the Paris tribunal judiciaire, which handles a heavy volume of CNF requests: file complete, keep copies of everything deposited, and diary the file, because a CNF request can take many months and any request for further documents should be answered fast and in full.

If the CNF is refused, or if nationality itself is disputed in the course of another case, the Code gives a direct court action. Article 29-3 provides: “Toute personne a le droit d’agir pour faire décider qu’elle a ou qu’elle n’a point la qualité de Français. Le procureur de la République a le même droit à l’égard de toute personne. Il est défendeur nécessaire à toute action déclaratoire de nationalité.” In plain terms, your child can ask the court for a declaration of French nationality, the procureur de la République (the state prosecutor) must be joined as a party, and the resulting judgment settles the question for all administrations. This is the proper forum for hard cases: disputed residence years, complex filiation, or a CNF refusal considered wrong. Prepare it like the declaration file, only more so, because the prosecutor will test every weak year.

Once French nationality is established and evidenced, the dual-nationality picture is favourable. On the British side, the government’s position is explicit: dual citizenship is allowed in the United Kingdom, so a person can be a British citizen and a citizen of other countries at the same time (dual citizenship rules). On the French side, neither the childhood declaration under article 21-11 nor automatic acquisition at eighteen under article 21-7 attaches any renunciation condition: the texts set residence and age conditions only, and they contain no requirement to give up British citizenship. Your child can therefore lawfully be both, and should in practice hold both passports: a French passport or national identity card evidencing European Union citizenship and an unconditional right to live, study and work in France, alongside a British passport preserving the right of abode in the United Kingdom and the link to the wider family. When travelling, the practical discipline is simple: show the French document to French and European Union border officers and the British document to British officers, and never let either passport lapse so long that proving the underlying nationality becomes an archaeological exercise. Renew each on time, keep both, and store the CNF itself, which unlike passports does not expire, with the family’s permanent papers.

Conclusion

A baby born in France to British parents starts life British and becomes French through residence, not through the place of birth alone. Check first whether the double jus soli exception applies, because a British parent who was personally born in France makes the baby French from day one. Otherwise, plan the article 21-11 declaration from the child’s thirteenth birthday, when the parents can act and the residence clock runs from age eight, rather than drifting towards eighteen and hoping the five years since eleven will speak for themselves. Keep the paper trail every year without exception: school attendance records, medical records, dated proof of holidays abroad, and the récépissé for every filing at the greffe. If a declaration is refused registration or a CNF application stalls, contest it before the tribunal judiciaire with the prosecutor joined, armed with the kind of concrete daily-life evidence the Court of Cassation rewards and the absence of which it punishes. Done in this order, the outcome is the best of both worlds that Brexit left intact: a child who is securely British by descent and securely French by declaration or by majority, carrying both passports and never again dependent on immigration paperwork in either country.