You moved to France before Brexit, or you arrived after it with a visa and a Withdrawal Agreement residence card, and now you are asking the question thousands of British residents ask every year: can I become French, keep my British passport, and secure my life here once and for all. The short answer is yes, naturalisation by decree remains open to British citizens, but it is a favour granted by the French state, not a right, and since Brexit you apply as a third-country national with no European Union shortcut. The residence clock, the language level, the employment record, the criminal record check and the quality of your file all matter, and a refusal is common where one of those pillars is weak. This guide explains, for a British reader, how French naturalisation by decree works after Brexit, what the five-year rule means when you hold a Withdrawal Agreement card, what assimilation really requires in practice, which documents British applicants struggle with, how the online procedure runs, how long it takes, what happens if the administration says no, and what dual nationality means on the British side. Every French legal term is explained at first use. The legal basis is the Civil Code, the case law of the Conseil d’Etat, France highest administrative court, and the administrative courts of appeal, plus the official service-public.fr guide checked on 16 July 2026 and the gov.uk guide on dual citizenship.

I. Am I eligible for French naturalisation by decree as a British citizen after Brexit

A. How long must I have lived in France before applying, and does my Withdrawal Agreement card count

Naturalisation by decree, called naturalisation par decret, is the standard route for a foreign adult who wants to become French on the basis of long residence and integration. The Civil Code states the principle in plain terms: “Hors le cas prévu à l’article 21-14-1 , l’acquisition de la nationalité française par décision de l’autorité publique résulte d’une naturalisation accordée par décret à la demande de l’étranger.” That sentence comes from Article 21-15 of the Civil Code. Three points matter for British readers. First, the procedure starts only at your request, called demande, filed by you. Second, the decision belongs to the public authority, which enjoys a wide discretion even when you meet every stated condition. Third, marriage to a French spouse follows a different declaration route, not this decree route, so this article deals only with the residence-based application most British residents use.

Two residence conditions sit at the heart of the file. You must live in France when the decree is signed, and you must show five years of habitual residence before you apply. The first rule is short and strict: “Nul ne peut être naturalisé s’il n’a en France sa résidence au moment de la signature du décret de naturalisation.” That is Article 21-16 of the Civil Code. In practice it means you cannot apply from London, move back to Kent while the file is pending, or keep only a holiday home in Dordogne while your real home is in Surrey. Your main home, your daily life and your centre of interests, called the siege of your material and moral interests by prefectures, must be in France on the day the decree is signed, not only on the day you apply.

The second rule sets the five-year clock: “Sous réserve des exceptions prévues aux articles 21-18 , 21-19 et 21-20 , la naturalisation ne peut être accordée qu’à l’étranger justifiant d’une résidence habituelle en France pendant les cinq années qui précèdent le dépôt de la demande.” That is Article 21-17 of the Civil Code. For a British applicant this raises three practical questions. When does the clock start. What breaks it. And whether time spent as an EU citizen before Brexit counts.

The clock counts backwards from the date you file on ANEF, the Administration Numerique pour les Etrangers en France, the online portal for foreign nationals. You need five years of habitual, lawful, continuous residence immediately before that date. Short holidays in the United Kingdom, school half-terms in Cornwall, or a work trip to Manchester do not break the clock. Long absences do. As a rule of thumb used by prefectures, absences of more than six months in one year, or repeated long stays outside France that shift your family, tax or working life back to Britain, lead the administration to say the residence is no longer habitual in France. If you split your life between the two countries, read our guide on how British couples prove tax residence after Brexit, because the same centre-of-interests evidence, home, bills, school, work, tax returns, is used in naturalisation to test where you really live.

Time spent before Brexit counts, provided it was lawful at the time and is followed without a break by lawful residence under the Withdrawal Agreement. A Briton who arrived in Lyon in 2016, lived here under EU free movement, then obtained a Withdrawal Agreement residence card, called carte de sejour accord de retrait du Royaume-Uni de l’Union europeenne, and kept an uninterrupted home in France, can rely on the whole period. A Briton who arrived in 2022 on a long-stay visa equivalent to a residence permit, then a multi-year card, starts the clock in 2022 and will in principle wait until 2027. What destroys the clock is a gap in lawful stay, called sejour irregulier, or a move of the main home back to the United Kingdom. An expired card that was renewed late with a retroactive receipt is usually explained, but months without any right of stay, or a year back in Bristol with only occasional trips to France, will push the starting point forward.

French law allows some absences to count as residence in France, but the list is narrow. The text provides: “Est assimilé à la résidence en France lorsque cette résidence constitue une condition de l’acquisition de la nationalité française : 1° Le séjour hors de France d’un étranger qui exerce une activité professionnelle publique ou privée pour le compte de l’Etat français ou d’un organisme dont l’activité présente un intérêt particulier pour l’économie ou la culture française ;” That extract comes from Article 21-26 of the Civil Code. The full article adds customs-union postings set by decree, service in a regular unit of the French army in peacetime or wartime, national service obligations, and national-service volunteering, with an extension to a spouse who actually lives with the beneficiary. Work for a British employer in London, remote work from a cottage in the Cotswolds, or a secondment to New York for an American group does not fall under this favour. The case law applies it strictly.

A useful illustration is the Nantes appeal court judgment of 7 July 2023, case number 21NT02547, concerning a man who invoked work for the World Health Organisation and long French schooling to claim the residence condition was met. The court reviewed Article 21-16, Article 21-17 and Article 21-26 and the 1993 implementation decree, then rejected the claim and upheld the refusal. The full reasoning is published at CAA Nantes, 7 July 2023, n° 21NT02547. For British readers the lesson is direct. International career prestige does not replace five years of habitual home in France, and short professional missions abroad after years in France are examined against where your spouse, children, home and tax remain. Keep boarding passes, but above all keep French rent receipts, French pay slips, French school certificates and French tax notices, called avis d’impot, for every one of the five years.

Shortened residence exists but rarely helps Britons. The service-public.fr guide F2213, the official page on naturalisation by decree, lists the main reductions: four years instead of five if you married a French citizen and lived together three years, five years of marriage if you lived abroad, ten years of schooling in a French school, refugee status, nationality of a French-speaking country where French is an official language, a French higher-education diploma after two years of study, exceptional integration through sporting, cultural, scientific, economic or civic contribution, and actual military service for France. British citizenship alone gives no reduction. English is not covered by the French-speaking-country favour, which concerns states where French has official status. A British child schooled ten years in a French college and lycee can use the schooling route, but an adult who arrived at forty with A-levels and a Manchester degree cannot. If you hold a French masters after two years at a French university, keep the diploma and transcripts, because that route genuinely shortens the wait.

B. Do I speak French well enough, know the Republic, work here and show good character

Residence alone never suffices. You must show assimilation to the French community, called assimilation a la communaute francaise, meaning language, knowledge of French history, culture and society, knowledge of the rights and duties of nationality, and adhesion to the essential principles and values of the Republic. The current wording, in force since 1 January 2026, states: “Nul ne peut être naturalisé s’il ne justifie de son assimilation à la communauté française, notamment par une connaissance suffisante, selon sa condition, de la langue, de l’histoire, de la culture et de la société françaises, dont le niveau et les modalités d’évaluation sont fixés par décret en Conseil d’Etat, et des droits et devoirs conférés par la nationalité française ainsi que par l’adhésion aux principes et aux valeurs essentiels de la République.” That passage is Article 21-24 of the Civil Code. The same article sets the language bar in functional terms: “L’intéressé justifie d’un niveau de langue lui permettant au moins de comprendre le contenu essentiel de sujets concrets ou abstraits dans un texte complexe, de communiquer avec spontanéité, de s’exprimer de façon claire et détaillée sur une grande variété de sujets.” In practice the administration requires a certified B2-level result for most adults, with limited exemptions for age, disability or long French schooling, and the exemption is interpreted narrowly.

Language failures remain the single most common ground for refusal among otherwise settled applicants, including Britons who live largely in English-speaking circles in Paris, the Dordogne or the Var. The Nantes court confirmed this approach on 2 April 2020 in case 19NT04015, where a woman argued that the prefecture interview had gone well enough for daily life and that her husband, daughter and grandchildren were French. The court recalled Article 21-24 and the language assessment rules, found the certified level insufficient, and upheld the rejection. The judgment is at CAA Nantes, 2 April 2020, n° 19NT04015. Do not rely on chatty fluency at the market. Book an approved test early, such as the TCF IRN or TEF IRN at B2 where required, prepare for abstract topics, and keep the certificate valid at filing and at the interview. If you have a French baccalaureate or a French university diploma, bring it, but still prepare to speak in detail about news, work and civic life at the entretien d’assimilation, the assimilation interview at the prefecture.

Assimilation also includes the civic examination and the interview. Since recent reforms, applicants take a civic exam, called examen civique, on French history, institutions, society and values, then an individual interview where the agent checks language in real conditions, knowledge of rights and duties, and adhesion to Republican principles such as equality between women and men, secularism in public life, called laicite, and respect for the law. At the end of the process you sign the Charter of Rights and Duties of the French Citizen, called charte des droits et devoirs du citoyen francais, which recalls the values you undertake to respect. Memorising dates helps, but the interview tests understanding. Be ready to explain, in French, what voting means, what paying tax funds, why school is compulsory, and how you take part in local life through work, associations, school councils or municipal events. Bring evidence of insertion, called insertion professionnelle et sociale: permanent contract, called CDI, or sustained self-employed income, pay slips, tax returns, health cover, children’s schooling, club membership, volunteering. A stable job in France weighs heavily. Long unemployment without explanation, undeclared cash work, or a life centred offshore with little French payroll or French tax, invites an adjournment, called ajournement, usually by two years.

Good character, called bonnes vie et moeurs, and the criminal record bar are examined separately and strictly. The Code states: “Nul ne peut être naturalisé s’il n’est pas de bonnes vie et moeurs ou s’il a fait l’objet de l’une des condamnations visées à l’article 21-27 du présent code. Les condamnations prononcées à l’étranger pourront toutefois ne pas être prises en considération ; en ce cas, le décret prononçant la naturalisation ne pourra être pris qu’après avis conforme du Conseil d’Etat.” That is Article 21-23 of the Civil Code. The cross-referenced bar covers the heaviest cases: “Nul ne peut acquérir la nationalité française ou être réintégré dans cette nationalité s’il a été l’objet soit d’une condamnation pour crimes ou délits constituant une atteinte aux intérêts fondamentaux de la Nation ou un acte de terrorisme, soit, quelle que soit l’infraction considérée, s’il a été condamné à une peine égale ou supérieure à six mois d’emprisonnement, non assortie d’une mesure de sursis.” That is the opening of Article 21-27 of the Civil Code, which also bars persons under an unlifted expulsion order, an unexecuted ban from French territory, or irregular stay. Even where no listed conviction exists, repeated fines for drink-driving, domestic incidents, fraud, undeclared work or unpaid support can lead to a finding of bad conduct.

The Nantes court applied this on 9 April 2024 in case 22NT03221, upholding a refusal based on criminal history despite an argument that rehabilitation, called rehabilitation de plein droit, had wiped the slate clean. The court examined Article 21-23, Article 21-27 and the Penal Code rules on rehabilitation, and held that the minister had lawfully found the good-character condition unmet. See CAA Nantes, 9 April 2024, n° 22NT03221. British applicants must therefore declare the full record on both sides of the Channel. A spent conviction under the UK Rehabilitation of Offenders Act 1974, a fixed penalty, a police caution, or an old French rappel a la loi must be understood for what each system asks. The French form asks about convictions, and the prefecture checks the French bulletin n°2 criminal record and police files. Hiding a conviction is far worse than explaining an old one with proof of change, because fraud can later undo the decree itself, as explained below. If you have any UK court outcome, take advice early, obtain the Police National Computer record or court memorandum where needed, and prepare a short, honest account with evidence of rehabilitation, steady work, family stability and community ties.

II. How the application actually works, how long it takes, and what to do if the answer is no

A. How do I file on ANEF, which British documents cause problems, and when do I get an answer

Filing is now online through ANEF for most of metropolitan France. You create an account, select naturalisation by decree, complete the personal, family, residence, work and tax sections, upload scans, then submit. The prefecture of your home address, called prefecture du domicile, examines admissibility, then schedules the assimilation interview, orders tax and police enquiries, and forwards the file with an opinion to the Ministry of the Interior, which decides. If the ministry grants the request, your name appears in a naturalisation decree published in the Journal officiel, the official gazette. If it refuses, it notifies a reasoned decision, called decision motivee, or in some admissibility cases a declaration of inadmissibility. Keep every ANEF receipt, email and summons. If you move house to another departement during the procedure, inform the platform immediately, because the competent prefecture changes and silence can be read as loss of residence.

British files fail most often on civil-status papers, called pieces d’etat civil. France runs on full birth, marriage and divorce records showing filiation, dates, places and marginal notes. A short UK birth certificate, the small green card without parents details, is not enough. Order a full certified copy of the birth entry, called a full birth certificate or GRO certificate, for each applicant and each British child named in the file. If you are married, add the full marriage certificate. If divorced, add the decree absolute plus proof it is final, with an official translation. If widowed, add the death certificate. Since 1 July 2023 the family record book, called livret de famille, is issued under tighter rules, but prefectures still expect coherent family proof, and any UK document in English needs a certified French translation by a sworn translator, called traducteur assermente, plus legalisation for France. The United Kingdom is party to the Hague Apostille Convention, so most UK civil records need an apostille from the UK Foreign, Commonwealth and Development Office, then translation in France. Order apostilled originals early, because the GRO plus apostille plus translation chain often takes weeks. Names must match across passport, residence card, birth certificate, marriage certificate, pay slips and tax returns. A middle name dropped in France but present on the UK passport, or a maiden-versus-married surname confusion, triggers requests for clarification. Write your name exactly as on the passport and explain any variant in a short cover note with evidence.

The fee is paid by electronic tax stamps, called timbres fiscaux electroniques. The official guide sets 255 euros per adult applicant, bought online and linked to the ANEF file. Keep the receipt. Exemptions are rare in this route, so budget for the stamp plus translations, apostilles, postage for GRO orders, travel to the test centre and to the prefecture interview, and, where needed, legal help to tidy the file before filing rather than after a refusal.

At the interview, bring originals of everything uploaded. The agent verifies identity, residence history, work, tax, family life, language and civic knowledge, and writes a report. Answer in French even if the agent speaks English. Dress and behave as for a formal administrative appointment. Do not bring children unless summoned. If your French is hesitant, do not ask a spouse to answer for you. The report will note that you could not sustain a conversation alone, which feeds directly into an assimilation refusal of the type upheld in the 2020 Nantes case cited above.

Deadlines matter and British applicants often misunderstand them. The administration has 18 months from the acknowledgment of a complete file to decide, reduced to 12 months if you have lived in France for ten years at filing. Silence for 18 months, or 12 months in the ten-year case, usually amounts to an implicit refusal you can challenge, but in practice many prefectures issue an explicit decision before that. After a grant, you are invited to a welcome ceremony, called ceremonie d’accueil dans la citoyennete, where the decree is presented and you sign the Charter mentioned above. Your French birth extract is then created at Nantes for persons born abroad, and you can apply for a French national identity card and passport. Registration on the electoral roll follows if you meet the civic conditions. Keep the Journal officiel reference and the ampliation, the certified copy of the decree, for life. Banks, notaires dealing with French property, and pension bodies will ask for it.

Honesty throughout is vital because a decree obtained by lie or fraud can be withdrawn. The Code provides: “Les décrets portant acquisition, naturalisation ou réintégration peuvent être rapportés sur avis conforme du Conseil d’Etat dans le délai de deux ans à compter de leur publication au Journal officiel si le requérant ne satisfait pas aux conditions légales ; si la décision a été obtenue par mensonge ou fraude, ces décrets peuvent être rapportés dans le délai de deux ans à partir de la découverte de la fraude.” That is Article 27-2 of the Civil Code. The Conseil d’Etat applied this on 5 April 2022 in case 457985, where an applicant naturalised in September 2018 had concealed a marriage in Cameroon in November 2017 despite a signed undertaking to report any change in personal and family situation. The Court recalled that: “Les décrets portant acquisition, naturalisation ou réintégration peuvent être rapportés sur avis conforme du Conseil d’Etat dans le délai de deux ans à compter de leur publication au Journal officiel si le requérant ne satisfait pas aux conditions légales ; si la décision a été obtenue par mensonge ou fraude, ces décrets peuvent être rapportés dans le délai de deux ans à partir de la découverte de la fraude”, verified the concealment, and upheld the withdrawing decree of August 2021. See CE, 5 April 2022, n° 457985. For British families this is a live risk where a separation, reconciliation, new partner, child or move is not updated on ANEF. If your situation changes after filing, upload the new certificate and inform the prefecture in writing without delay. A quiet divorce in Maidstone or a new civil partnership will surface through data checks, and the price is loss of nationality, not a fine.

Practical evidence tips for Britons help avoid the classic adjournment. File French tax returns for each of the required years, even in a first year with little French income, and keep the avis d’impot. Keep five years of rent receipts or mortgage statements, electricity and broadband bills, home insurance, and health cover proof. If you use an S1 for healthcare as a posted worker or pensioner, keep the registration trail coherent with residence and tax, and see our explainer on S1 healthcare and CPAM reimbursement before registration where relevant. Keep employment proof continuous: contracts, last three pay slips per year, employer attestations, and, if self-employed, URSSAF statements and accounts. If you own a French company or work remotely for a UK employer from France, ensure the work is lawful under your residence status and declared in France for tax and social charges where due, because a mismatch between the prefecture file, the tax file and the URSSAF file is a standard reason to pause the case.

B. What happens if the prefecture or the ministry says no, how do I challenge it, and do I stay British

A refusal is not one single thing. You must read which legal form you received. An irrecevabilite, a finding of inadmissibility, says a threshold condition is missing, such as less than five years of habitual residence, incomplete file, or lack of lawful stay. An ajournement, an adjournment, usually for two years, says you are broadly eligible but assimilation, integration or good character is not yet established, for example language just below the mark, too recent arrival in stable work, or a recent driving conviction. A rejet, an outright rejection, is a substantive no on the merits after full examination. The letter must give reasons in fact and law, called motifs de fait et de droit, and state the remedies and time limits. Keep the envelope and the ANEF notification date, because time runs from notification.

The first remedy is usually a gracious or hierarchical appeal, called recours gracieux devant le ministre or recours hierarchique, asking the decision-maker or the minister to reconsider with new evidence. For naturalisation the key deadline is two months from notification to file this administrative appeal, and silence for two months on that appeal is treated as a rejection, which then opens the judicial route. The judicial route is an action for excess of power, called recours pour exces de pouvoir, before the Nantes administrative tribunal, which has national jurisdiction for naturalisation refusals, with appeal to the Nantes administrative court of appeal and possible cassation to the Conseil d’Etat on points of law. Lodge the tribunal claim within two months of the explicit or implicit rejection of the administrative appeal. A late claim is inadmissible, however strong the merits. Ask for what the judge can grant: annulment for legal error, procedural flaw or manifest error of assessment, and, where appropriate, an order to re-examine. The judge does not grant nationality directly in place of the minister except in narrow injunction cases, so frame the request as annulment plus re-examination within a set time.

Choose the remedy by reading the reason. If the reason is language level and you have since passed a higher certified test, re-take the test, add six months of evening classes, gather proof of French-language work meetings, parent-teacher meetings and association life, then file a well-documented administrative appeal within the two months and, in parallel, prepare to reapply after the adjournment period if the appeal fails. If the reason is residence duration, counting shows whether an appeal can succeed or whether waiting is wiser. An applicant refused at four years and eight months with continuous stay will often do better to let the clock run, build two more tax years, then file a fresh, stronger request rather than litigate arithmetic. If the reason is criminal history, obtain the exact French bulletin record, the court judgment, proof of sentence served, fines paid, compensation paid, and evidence of steady conduct since, then take advice on whether the bar in Article 21-27 or the discretion in Article 21-23 applies. The 2024 Nantes case above shows that invoking rehabilitation alone, without addressing the underlying conduct and the minister assessment power, does not carry the day. If the reason is undisclosed work or tax gaps, regularise first with the tax office and URSSAF, pay, obtain clearance, work six to twelve months clean, then reapply with a coherent story.

Reapplying after an adjournment is normal and often succeeds where the applicant treats the waiting period as a to-do list. Keep the refusal letter, diarize the end of the adjournment, and return with what was missing: higher language certificate, permanent contract, completed training, community involvement, clean driving record, paid fines, settled debts. Do not file an identical file the next month. The second examiner will compare the two files line by line, and an unchanged reapplication confirms the first decision. If you married a French citizen in the meantime, or completed a French degree, check whether a different route, such as declaration by marriage after the required community of life, now fits better, but do not mix routes in one letter. One clear legal basis per application, with evidence mapped to each condition, is read faster and refused less.

Dual nationality is the final worry for most British applicants, and the British side is reassuring. The United Kingdom permits dual nationality. The official gov.uk page on dual citizenship confirms that you do not need to give up British citizenship to acquire another nationality and that you remain British while holding a second passport, subject to advice on travel and consular protection: see gov.uk dual citizenship. On the French side, France in principle allows dual nationality with the United Kingdom, but individual history can raise questions, for example prior service, prior loss, or a prior renunciation, so check your own position and, where the family story is complex, take advice before the ceremony rather than assuming. Once French, you travel as French within the European Union and as British where that helps, you vote in France where entitled, you access French consular protection, and your children born afterwards may benefit from French nationality under the rules on filiation and birth in France. Keep both passports valid, use the same name spelling for airline tickets and border crossings, and remember that entering the United Kingdom as a British citizen and leaving and entering France as a French citizen is the clean pattern most dual nationals adopt.

The official French guide to follow alongside this article is the service-public.fr page on naturalisation by decree, fiche F2213, which sets out conditions, filing, interview, fee, delays and remedies with links to ANEF: see service-public.fr F2213 French nationality by decree. Read it on the day you file, because forms, test lists and prefecture practice change. If your case involves a recent conviction, a fragmented five years, long absences for UK caring duties, or complex UK family papers, build the file with a lawyer before ANEF submission. A refusal costs two years. A careful first file often avoids it.

Conclusion

For British residents, French naturalisation by decree after Brexit is entirely achievable, but it rewards residents who think like a prefecture. Five years of real, lawful, habitual home in France with no gap, a Withdrawal Agreement card or successor title kept valid throughout, certified French at the required level with confident spoken use, a clean civic interview and signed Charter, steady lawful work declared and taxed in France, and a clean record of conduct form one coherent story. The Code sets each test in short sentences that leave little room for improvisation, from residence at signing to five years before filing, from assimilation and language to good character and conviction bars, with fraud withdrawal within two years of discovery as the ultimate reminder to disclose everything. Courts uphold refusals where language, residence or conduct falls short, and they uphold withdrawals where marriage or family change was hidden, as the 2020, 2023 and 2024 Nantes judgments and the 2022 Conseil d’Etat fraud case show. File a complete ANEF case with full apostilled British certificates and sworn translations, pay the 255 euro stamp, attend the interview in French with originals, update the file if life changes, and calendar the 18-month decision period and the two-month appeal periods. Do that, and you give yourself the best chance of hearing your name in the Journal officiel, attending the welcome ceremony, and living in France with both passports in the drawer, British and French, for whatever the next decade brings.

Need a quick opinion on your case.

Our firm offers a telephone consultation within 48 hours with a lawyer of the firm for British residents considering French naturalisation. Call +33 6 46 60 58 22 or write via our contact page. Bring your residence card, your five-year timeline and your language certificate, and we will tell you whether to file now, wait, or strengthen the file first.