Your baby has just been born in a French maternity ward, the officier de l’état civil (the registrar at the town hall, the mairie) is waiting for the birth declaration, and two administrations already seem to be asking questions at once. France wants to know whether this newborn is French. Britain wants to know whether the child is British. The health fund, the CPAM (caisse primaire d’assurance maladie, your local state health insurance fund), wants to know under which scheme the baby is covered, and the airline will soon want to see the child’s own travel document. Since Brexit, British parents in France no longer benefit from European Union citizenship, so every one of these questions is answered by national law on each side of the Channel, and the two answers do not always match. The good news is that in the overwhelming majority of cases the child ends up with solid rights in both countries, and where an administration says no, each refusal has its own judge and its own remedy. This article explains, step by step, whether a baby born in France to British parents is French, whether the baby is British, which papers to file and in what order, how healthcare cover works from the first day, how the child travels, and how to challenge every refusal you might meet along the way.

I. Is our baby French, British or both? How nationality works for a child born in France to British parents after Brexit

A. Is our baby French at birth? The three narrow doors, and why most British babies are not French on day one

Many British parents assume that being born on French soil makes a baby French. It does not, or at least not in the situation most British families are in. French nationality law, which sits in the Code civil (the Civil Code), works with a short list of doors, and birth in France alone opens none of them for the child of two British parents who were themselves born in Britain. Understanding the three doors that can apply at birth saves you from a very common mistake: asking the registrar for a certificat de nationalité française (certificate of French nationality) for a newborn who cannot yet have one, being refused, and then worrying that something has gone wrong when nothing has.

The first door is bloodline, jus sanguinis. Article 18 of the Civil Code provides: « Est français l’enfant dont l’un des parents au moins est français. » In plain English: a child is French where at least one parent is French. If neither you nor the other parent is French, this door stays shut, however long you have lived in France and whatever residence permit you hold. A carte de séjour (residence permit), even a permanent one, even one issued under the Withdrawal Agreement that organised Brexit, is not nationality. Only a French parent makes a French baby at birth.

The second door is sometimes called double jus soli, and it matters to a small but real number of British families: those where one parent was personally born in France. Article 19-3 of the Civil Code provides: « Est français l’enfant né en France lorsque l’un de ses parents au moins y est lui-même né. » So if you are British but you were yourself born in France, perhaps because your own parents lived there in the 1980s or 1990s, your baby born in France is French from birth, even though you are British. This surprises many second-generation expatriates, and it is worth checking, because it changes everything that follows: a French child needs no residence permit, ever, and travels as a French citizen. If neither parent was born in France, this door stays shut too.

The third door at birth is a safety net for children who would otherwise have no nationality at all. Article 19-1 of the Civil Code 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. » This provision exists so that no child born in France ends up stateless. For British parents it is normally irrelevant, because British nationality law does transmit to a baby born abroad, as explained below, so the baby is British and never stateless. The same Code also covers the extreme case of a child of unknown parents: article 19 of the Civil Code states « Est français l’enfant né en France de parents inconnus. » Again, this is not your situation if parentage is established, but it completes the picture: the Code lists every door, and none of them opens at birth for the ordinary case of a baby born in France to two British parents born in Britain.

That is not the end of the story, because French law gives that child two later routes to become French while growing up in France. The first and most powerful is automatic acquisition at eighteen. Article 21-7 of the Civil Code 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. » Read carefully: at eighteen, the child becomes French automatically, with no application and no discretion, provided two residence conditions are met, residence in France at eighteen and five years of habitual residence in France since the age of eleven. The five years can be broken up; holidays in Britain and school terms in France still count as habitual residence in France. This is the provision that quietly turns thousands of British teenagers raised in France into French adults every year, and it operates by law, whether or not anyone applies for a certificate.

The catch is proof. Administrations sometimes refuse the certificate that records this nationality, arguing that schooling or residence was not continuous enough, and families then have to prove year by year where the child lived. A recent judgment shows exactly how courts handle that exercise. On 20 April 2026, the tribunal judiciaire of Béziers (the local civil court that hears nationality cases) ruled on a young man born in France to foreign parents whose request for a certificate had been refused for lack of proof of five years’ residence since age eleven. The court recalled the rule in these terms: « Aux termes de l’article 21-7 alinéa 1er du code civil « 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 [Etablissement 1] pendant une période continue ou discontinue d’au moins cinq ans, depuis l’âge de onze ans ». » It then rebuilt the residence history piece by piece, accepting school certificates, a youth employment support record and even a vaccination record and a doctor’s appointment as evidence of presence, and it concluded: « ORDONNE la délivrance d’un certificat de nationalité française » (Tribunal judiciaire de Béziers, 20 April 2026, RG 25/01671). The lesson for British parents is practical and starts now: keep everything. School certificates (certificats de scolarité), medical records, club memberships, tax household records showing the child at your address. Your newborn will need them in eighteen years, and the Béziers case proves that ordinary family paperwork wins these cases.

The second later route is faster: an anticipated declaration during the teenage years. Article 21-11 of the Civil Code provides: « 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. » In practice, parents can claim French nationality on the child’s behalf from age thirteen, and the teenager can claim it personally from sixteen, with a shorter residence window for the younger route. The child’s consent is required. For a British family settled in France, this is often the moment when the teenager’s status is put in order before university applications, driving licences and first jobs, and it is well worth diarising now, even with a newborn in your arms.

B. Is our baby British? Citizenship by descent, dual nationality and the British passport

Turn now to the British side, where the answer is almost always yes. A child born outside the United Kingdom to a British parent is normally British automatically, by a mechanism lawyers call citizenship by descent. The official government guidance explains that British citizenship normally passes down one generation to children born outside Britain (see GOV.UK, British citizenship and your British parent). Concretely, if you are a British citizen yourself, and you are British otherwise than by descent, which is the case if you were born in Britain, your baby born in France is British from birth, with no registration and no application needed to be British. You will still need a passport to prove it and to travel, but the status itself is automatic.

Two refinements matter. First, the one-generation rule. Because your baby is British by descent, the baby’s own future children, your grandchildren, will not automatically be British if they too are born outside Britain. The same guidance warns that the next generation, children themselves born outside Britain, do not acquire citizenship automatically. If your child grows up in France, marries there and has children there, those grandchildren will need registration, not automatic transmission. This is the single most overlooked consequence of raising a British family abroad, and it is the reason some families later register births with the British authorities or plan a period of residence in Britain. Second, if your own situation is unusual, for example you are British by descent yourself, or you were born outside Britain, or only one parent is British and the parents are unmarried with questions over parentage, the automatic answer may not apply and registration may be needed. The same GOV.UK pages set out the routes by date of birth and parental situation, and each route has its own form, fee and evidence list.

Dual nationality is the next worry, and here the answer is reassuring on both sides. France accepts dual nationality without restriction: your child can be French under article 21-7 or 21-11 and remain British, with no obligation to choose at eighteen. Britain likewise imposes no requirement to renounce. Your child can therefore hold both passports for life, vote in both countries when the franchise rules allow, and pass each nationality on according to each country’s own transmission rules. Neither country treats the other nationality as a problem, and Brexit changed nothing about this: dual British-French nationality was lawful before Brexit and remains lawful now.

Proving British nationality means getting a British passport, applied for from France through His Majesty’s Passport Office, with the baby’s French birth certificate, evidence of the British parent’s status, and compliant baby photographs. Many families also register the birth with the British consulate, which creates a British consular birth record in English and can simplify later applications, though it is optional and does not itself grant nationality. Expect the passport process to take weeks rather than days, and do not book non-refundable travel for the baby until the document is in hand. If the passport office queries parentage, marriage, or the father’s status on the birth certificate, answer with certified documents rather than explanations: the French acte de naissance (birth certificate) with both parents named, the parents’ own birth certificates and passports, and where needed a sworn translation by a traducteur assermenté (sworn translator). A refusal or a prolonged delay can be challenged through the passport office’s complaints process and, ultimately, by judicial review in Britain, but most cases are resolved with one complete, well-evidenced file.

II. After the birth in France: papers to file, healthcare cover and travel, plus how to challenge every refusal

A. What papers must we file and how is our baby covered for healthcare? Birth declaration, birth certificate, CPAM cover and the S1

The first deadline arrives fast. Article 55 of the Civil Code provides: « Les déclarations de naissance sont faites dans les cinq jours de l’accouchement, à l’officier de l’état civil du lieu. » The birth must be declared within five days of delivery to the registrar of the place of birth. In practice the maternity ward often handles the paperwork or guides you to the town hall, and the father, the mother, a relative, or hospital staff can make the declaration. Missing the deadline does not leave the child without civil status, but it forces a court judgment to record the birth late, so treat the five days as absolute, count carefully around weekends and public holidays, and keep the receipt the registrar gives you.

The declaration produces the acte de naissance, the French birth certificate, whose contents are fixed by law. Article 57 of the Civil Code states: « L’acte de naissance énoncera le jour, l’heure et le lieu de la naissance, le sexe de l’enfant, les prénoms qui lui seront donnés, le nom de famille, suivi le cas échéant de la mention de la déclaration conjointe de ses parents quant au choix effectué, ainsi que les prénoms, noms, âges, professions et domiciles des père et mère et, s’il y a lieu, ceux du déclarant. » Two points deserve attention from British parents. First, the surname: French law lets parents choose, by joint declaration, which surname the child bears, the father’s, the mother’s, or both joined, and the choice for the first child normally governs later siblings. Discuss this before the declaration, because changing it afterwards requires a formal procedure. Second, naming both parents on the certificate matters enormously for everything that follows, from British citizenship evidence to healthcare attachment to inheritance. An unnamed father on the certificate creates difficulties that take years to undo, so make sure parentage is fully recorded from the start.

Order several full copies (copies intégrales) of the birth certificate from the town hall at once: you will need them for the British passport, the health fund, family benefits, and later the nationality declaration. If one parent is French or was born in France, ask the registrar or later the nationality desk whether a mention of French nationality should already appear; if the answer is no, do not panic, since for most British babies French nationality comes later through articles 21-7 or 21-11, not at birth.

Healthcare cover starts immediately, and the mechanism depends on the parents’ situation. The standard route for the baby is attachment as a dependant, an ayant droit, to an insured parent. Article L160-2 of the Social Security Code provides: « bénéficient de la prise en charge de leurs frais de santé en tant qu’ayants droit d’un assuré social les enfants mineurs n’exerçant pas d’activité professionnelle qui sont à sa charge, à condition que la filiation, y compris adoptive, soit légalement établie » Once parentage is legally established, which the birth certificate does, the baby is covered for healthcare costs as the insured parent’s dependant. Declare the newborn to your CPAM as soon as the birth certificate is issued, through your compte ameli (online health insurance account) or at the counter, and the child is added to the parent’s carte Vitale (the green electronic health card) or given linked rights. From sixteen the child can request cover in their own right, but for a baby the dependant route is the whole story.

The parent’s own cover is the foundation, and here British families post-Brexit fall into three groups. If a parent works in France, employed or self-employed, that parent is insured through work and the baby attaches to them. If a parent does not work but lives in France lawfully and stably, the universal residence-based scheme, the PUMA (protection universelle maladie), covers them. Article L160-1 of the Social Security Code provides: « Toute personne travaillant ou, lorsqu’elle n’exerce pas d’activité professionnelle, résidant en France de manière stable et régulière bénéficie, en cas de maladie ou de maternité, de la prise en charge de ses frais de santé dans les conditions fixées au présent livre. » Stable and regular residence is assessed under detailed rules, with article L111-2-3 of the same Code sending to a decree for the test of stability and regularity. In practice the fund looks at three months of presence and lawful stay, so a British mother living in France on a Withdrawal Agreement card or a valid carte de séjour qualifies, and her baby attaches to her. Keep proof of lawful stay and address from the start, because the fund will ask for it.

The third group is families where a parent remains insured in Britain and posted or retired into France with a portable document. The key document is the S1 healthcare certificate, which shifts the cost of the family’s French healthcare to Britain while care is delivered in France. The official British guidance explains the mechanism and instructs families to register the S1 with the local CPAM (see GOV.UK, Healthcare for UK nationals living in France). That registration step is where files stall: the CPAM sometimes queries the S1, asks for translations, or opens a PUMA file instead. Insist on registration of the S1 as such, keep copies of everything submitted, and note the date of submission, because cover should follow from the entitlement, not from the fund’s processing speed. For trips back to Britain, the baby travels on the parent’s planning: a baby covered in France uses a French-issued European Health Insurance Card for temporary stays in the EU, while the British side uses the Global Health Insurance Card for visitors, and the two systems must not be confused at the hospital desk.

Maternity costs themselves deserve one sentence of reassurance: the mother’s pregnancy and delivery are covered under her own French rights, salaried, self-employed, PUMA or S1, and the baby’s first care in the maternity ward follows the baby’s attachment once declared. If the CPAM refuses to register the baby, or registers the baby late and a bill arrives, challenge in writing first through the fund’s complaints channel, then through its commission de recours amiable (amicable appeals board), and then before the health disputes division of the tribunal judiciaire. Deadlines are short and stated on each decision letter, so calendar every date the moment a refusal arrives, and never let a refusal sit unanswered while bills accumulate.

B. Can our baby travel and stay with us without a residence permit? Passports, borders and how to challenge a refusal

British parents often ask whether their French-born baby needs a titre de séjour, a residence permit, to live in France. The answer is no, and the reason is simple arithmetic in the statute. Article L411-1 of the Code on the Entry and Stay of Foreigners (CESEDA) imposes the permit obligation in these terms: « Sous réserve des engagements internationaux de la France ou du livre II, tout étranger âgé de plus de dix-huit ans qui souhaite séjourner en France pour une durée supérieure à trois mois doit être titulaire de l’un des documents de séjour suivants : » Only foreigners over eighteen must hold a stay document for stays over three months. A minor child, whatever their nationality, is not subject to the obligation, and no prefecture (préfecture, the state authority that issues permits) can require a residence permit for your baby. The child’s right to live with lawfully resident parents follows from the parents’ own lawful stay, and that is the end of the permit question until adulthood.

Travel is a different matter, because airlines and border officers check documents, not statutes. The baby needs their own travel document for any international trip: a British passport, or a French passport or identity card if the child is French, with no piggybacking on a parent’s passport since individual documents became the rule. For a British baby living in France, the practical file for each trip is therefore the baby’s British passport plus, for re-entry into France, evidence of the family’s lawful residence in France, such as the parents’ residence permits and proof of address. Carry the birth certificate or a family record booklet copy as well when only one parent travels with the baby, since officers on both sides sometimes question a lone adult travelling with an infant, and a short authorisation letter from the other parent with a copy of their passport defuses most checks. Plan passport applications months before any booked travel: a baby cannot fly on an application receipt, and peak-season processing slows every year.

Refusals, when they come, each have their own forum, and mixing them up loses time. If the nationality desk (greffe) refuses the certificat de nationalité française for your teenager years from now, the challenge goes to the tribunal judiciaire, exactly as in the Béziers case, where the court ordered the certificate after rebuilding residence from school, employment-support, vaccination and health-fund records. Start that file today by archiving the records the Béziers judges relied on. If the CPAM refuses the baby’s attachment or the S1 registration, the route runs through the fund’s internal appeal board and then the health disputes bench of the tribunal judiciaire, with the refusal letter’s deadline governing everything. If the town hall refuses to record the birth declaration or to issue copies, the procureur de la République (public prosecutor) and then the tribunal judiciaire can order the registrar to act. If a prefecture wrongly demands a permit for the child or refuses the parents’ own renewal in a way that destabilises the family, the challenge goes to the tribunal administratif (administrative court), where interim relief (référé) can suspend a harmful decision in days. And if the British passport office stalls, its complaints ladder and ultimately British judicial review apply. In every forum the winning pattern is the same: the refusal letter, the complete supporting file, and action inside the stated deadline.

One final Brexit-specific warning. Before Brexit, a British parent’s European Union citizenship smoothed over many gaps: an unregistered delay here, a missing document there, rarely mattered. That tolerance is gone. Lawful stay must now be continuously evidenced, health cover must sit on the correct legal basis rather than administrative goodwill, and the child’s future French nationality at eighteen will depend on residence records nobody else will keep for you. The families who sail through are not the lucky ones; they are the organised ones, with a folder, physical or digital, holding birth certificates, passports, permits, school records, health attestations and every decision letter with its date stamp. Build that folder this week, while the baby sleeps.

Conclusion

A baby born in France to British parents after Brexit is British from birth in the ordinary case, by descent through the British parent, and is generally not French at birth, because French law opens nationality at birth only through a French parent, a parent personally born in France, or the statelessness safety net. French nationality then arrives later for the child raised in France, automatically at eighteen under article 21-7 or by anticipated declaration from thirteen or sixteen under article 21-11, with dual nationality fully accepted on both sides. The paperwork follows a strict order: birth declaration within five days, full copies of the birth certificate, immediate declaration to the CPAM as a dependant, S1 registration where Britain funds the cover, and the baby’s own passport before any travel, with no residence permit needed for a minor. Each refusal has its remedy, from the tribunal judiciaire for nationality certificates and health-fund disputes to the tribunal administratif for permit decisions, and the decided cases show that complete, dated evidence wins. Keep every record from day one, diary the teenage nationality declaration, and treat every decision letter as the start of a deadline, not the end of the story.

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