You settled in France, kept your house in Britain, and now two tax offices are taxing the same income. The French tax administration, the DGFiP, treats you as domiciled in France and taxes your worldwide income. HM Revenue and Customs, HMRC, treats you as resident in the United Kingdom under its own Statutory Residence Test and taxes you again. Each side is applying its own domestic law correctly, and that is exactly why the dispute exists. Brexit did not rewrite the tax treaty between the two countries, but it multiplied the situations that create dual claims: long-stay visas that assume French settlement, British homes retained for returns to see family, consultancy work performed in both countries, and retirement split between the Dordogne and the south coast. This article explains, for a British reader, how France decides that you live here for tax purposes, how the United Kingdom runs a completely different test, how Article 4 of the France-United Kingdom tax treaty of 19 June 2008 breaks the tie in four ordered steps, and what to do in practice when the bill you received taxes income it should not tax. French legal terms are explained as they appear, and every decisive proposition is tied to the exact text that supports it.
I. Why France and the United Kingdom can both claim you at the same time
A. How France decides that your tax home is here, and why owning a flat is rarely enough
French domestic law starts with a short rule that has very large consequences. Article 4 A of the General Tax Code, the Code général des impôts, the statute that governs income tax, provides: “Les personnes qui ont en France leur domicile fiscal sont passibles de l’impôt sur le revenu en raison de l’ensemble de leurs revenus. Celles dont le domicile fiscal est situé hors de France sont passibles de cet impôt en raison de leurs seuls revenus de source française.” In plain English, a person whose tax home, the domicile fiscal, is in France pays French income tax, the impôt sur le revenu, on worldwide income, while a person whose tax home is outside France pays French tax only on French-source income. Everything therefore turns on the definition of the domicile fiscal, and that definition is given by Article 4 B of the same Code: “1. Sont considérées comme ayant leur domicile fiscal en France au sens de l’article 4 A : a. Les personnes qui ont en France leur foyer ou le lieu de leur séjour principal ; b. Celles qui exercent en France une activité professionnelle, salariée ou non, à moins qu’elles ne justifient que cette activité y est exercée à titre accessoire ;” A third limb adds: “c. Celles qui ont en France le centre de leurs intérêts économiques.” Three French expressions need explanation. The foyer is the home in the family sense, the place where you normally live and centre your personal life. The séjour principal is the place of your main physical stay. The centre des intérêts économiques is the centre of your economic interests, where your money, investments and business substance sit. Meeting any single one of the three limbs is enough for France to claim you, which is why so many British profiles fall inside the French net: a spouse and children in school in France, a French employment contract alongside occasional London work, or a portfolio managed from a French address.
Two features of this French test surprise British readers. First, the statute states no number of days. Unlike the British test described below, Article 4 B counts no 183 days and no 91 days; it looks at where your life is centred through a bundle of evidence, a faisceau d’indices. Day counts matter as evidence of where you actually live, but no threshold in the statute makes you resident or non-resident by itself. Second, the treaty can switch the French answer off. The same Article 4 B ends with a shield clause: “Les personnes qui satisfont à l’un au moins des critères fixés aux a à c du présent 1 ne peuvent toutefois pas être considérées comme ayant leur domicile fiscal en France lorsque, par application des conventions internationales relatives aux doubles impositions, elles ne sont pas regardées comme résidentes de France.” Even if you meet a domestic limb, France must let go if the tax treaty does not regard you as a French resident. That sentence is the doorway to the tie-breaker examined in Part II, and it is why a dual-residence file must always be argued on two levels, domestic law first, treaty second.
The courts have given the foyer a precise content, and two recent decisions of the Conseil d’État, the supreme court for tax disputes, show how demanding that content is. In a decision of 11 May 2022, no. 450692, a divorced father working for a construction company in Saudi Arabia owned a flat in Rennes, stayed there on leave and paid maintenance for his two minor children living in France. The lower court treated those facts as proof that his foyer was in France. The Conseil d’État quashed that reasoning and stated the rule for a single taxpayer: “le foyer d’un contribuable célibataire s’entend du lieu où il habite normalement et a le centre de sa vie personnelle, sans qu’il soit tenu compte des séjours effectués temporairement ailleurs en raison des nécessités de la profession ou de circonstances exceptionnelles. Le lieu du séjour principal de ce contribuable ne peut déterminer son domicile fiscal que dans l’hypothèse où il ne dispose pas de foyer.” The home of a single taxpayer means the place where he normally lives and centres his personal life, ignoring temporary stays elsewhere imposed by work, and the place of main stay can only decide tax home where there is no foyer at all. Applying that rule, the court held: “En se fondant sur ces éléments, qui ne sont pas suffisants à eux seuls pour établir le lieu où le contribuable habitait normalement et avait le centre de sa vie personnelle, la cour a commis une erreur de droit.” Ownership of a French flat plus holiday stays plus children in France was not enough, by itself, to fix the foyer in France. For British readers who kept a pied-à-terre in Paris while working in London, that holding cuts both ways: a retained flat does not automatically make you French-resident, but the administration will combine it with every other link, and the file is won or lost on the full bundle.
For a married taxpayer the test looks at the centre of family interests, and the administration’s bundle is wider. In a decision of 9 June 2021, no. 431551, the Conseil d’État recalled: “le foyer s’entend du lieu où le contribuable habite normalement et a le centre de ses intérêts familiaux, sans qu’il soit tenu compte des séjours effectués temporairement ailleurs en raison des nécessités de la profession ou de circonstances exceptionnelles, et le lieu du séjour principal du contribuable ne peut déterminer son domicile fiscal que dans l’hypothèse où celui-ci ne dispose pas de foyer.” The court then approved findings built on exactly the kind of administrative traces British households leave behind: French housing tax, the taxe d’habitation, paid for the dwelling where the spouse lived, a French address entered on the identity card at renewal, no family link in the other country, and even the pattern of current expenditure and the water consumption of the spouse’s home. The court concluded: “En se fondant sur ces éléments pour en déduire que M. A… avait en France son foyer et en confortant son analyse par l’examen du lieu des dépenses courantes de M. A… et de l’état des consommations d’eau du logement de son épouse, la cour n’a pas commis d’erreur de droit ni dénaturé les pièces du dossier.” Practical lesson: when your spouse and children live in France, when your official documents show a French address and your daily spending flows through French accounts, contesting French domicile is an uphill case, and energy is usually better spent on the treaty tie-breaker and on the correct computation of the bill than on denying the obvious.
The second and third limbs of Article 4 B deserve the same attention because they catch profiles the foyer analysis misses. Professional activity in France makes you French-domiciled unless you prove it is merely accessory, which is a narrow escape: a London employment performed remotely from a French home for most of the year is not accessory work, and the administration increasingly asks where the work was physically done rather than where the employer sits. The centre of economic interests catches the investor whose family arrangements look British but whose rental flats, bank mandates, company directorships and management decisions sit in France. Each limb is sufficient on its own, so a British consultant living in London but directing a French property business, or a retiree in the United Kingdom drawing most income from French assets, can be claimed by France without ever meeting the foyer test.
B. How the United Kingdom counts days, homes and ties, and why that test overlaps with the French one
The British test works nothing like the French one, and the mismatch is the engine of dual residence. Since 2013 the United Kingdom applies a statutory scheme, the Statutory Residence Test, set out in HMRC guidance RDR3 and summarised on the official gov.uk page on residence. The starting point is mechanical. As gov.uk explains, United Kingdom residence follows where at least one automatic UK test or the sufficient ties test is met and none of the automatic overseas tests applies; otherwise the person is non-resident for United Kingdom tax purposes. Three automatic UK tests matter most for Britons in France: spending 183 days or more in the United Kingdom in the tax year; having an only home in the United Kingdom for 91 consecutive days or more, with at least 30 days of visit or stay there in the tax year; and full-time work in the United Kingdom. Failing those, a sufficient-ties test combines days spent in the United Kingdom with family, accommodation, work and presence ties, so that even modest day counts can make you resident where ties are strong. Mirror-image overseas tests can make you conclusively non-resident, notably where fewer than 16 days were spent in the United Kingdom, extended to 46 days for those not UK-resident in the three previous tax years, or where full-time work abroad fits within strict day limits.
Two consequences follow for a British household in France. First, keeping a British home and spending school holidays, Christmas and long summer weeks there can preserve UK residence under the only-home test or the ties test even after a French long-stay visa and a French carte de séjour, the residence permit, suggest settlement in France. France sees the spouse, the children and the daily spending and claims the foyer; the United Kingdom counts the days, the retained home and the family ties and claims residence too. Neither administration is misreading its own law. Second, the year of the move itself is softened on the British side by split-year treatment: where a person moves in or out of the United Kingdom, the tax year is generally divided into a non-resident part and a resident part, so that United Kingdom tax on foreign income follows only the period of living there. France has no equivalent splitting of the year for the domicile test, so the arrival year and the departure year are the classic dual-claim years and should be prepared as such from the start, with travel calendars, boarding passes, tenancy agreements and employer letters kept year by year.
Readers sometimes assume Brexit changed these residence rules. It did not. Tax residence was never harmonised at European level, and the France-United Kingdom treaty continues to allocate taxing rights exactly as before. What Brexit changed is the population caught by the overlap: before 2021 many Britons lived in France without visas and without thinking about residence, moving fluidly between two homes. Since 2021 settlement in France requires a visa and a documented life here, while life in Britain continues through retained homes and frequent returns, so each administration now holds paper proving its own claim. A dual-residence file is therefore no longer an exotic accident; it is the normal condition of the British household genuinely living between the two countries, and it must be resolved by the treaty, not by choosing whichever answer feels convenient.
II. The treaty that breaks the tie, and the remedies when the bill is wrong
A. Article 4 of the France-United Kingdom treaty: the four-step cascade that names a single winner
Where each country is entitled, under its own law, to treat you as resident, the treaty steps in and designates exactly one country of residence. The mechanism is Article 4 of the France-United Kingdom convention of 19 June 2008, published by the French decree that carries it into domestic law. Its first paragraph defines the persons concerned in functional terms: anyone whom either state’s legislation subjects to tax by reason of domicile, residence, place of management, place of registration or any similar criterion counts as a resident of that state for treaty purposes. A resident of a contracting state is anyone whom that state’s legislation subjects to tax by reason of domicile, residence or any similar criterion. The Cour de cassation, the supreme court for civil and commercial matters, described exactly this architecture when interpreting the identically worded residence article of another French treaty: the article “définit, en son paragraphe 1, le résident d’un Etat contractant comme toute personne qui, en vertu de la législation dudit Etat, est assujettie à l’impôt dans cet Etat en raison de son domicile, de sa résidence, de son siège de direction ou de tout autre critère de nature analogue. Son paragraphe 2 détermine les règles permettant de résoudre le cas dans lequel une personne physique est considérée comme résident de chacun des Etats contractants” (Commercial Chamber, 11 March 2026, no. 25-10.235). Paragraph 1 records the dual claim; paragraph 2 resolves it. Although that ruling concerned the Franco-Swiss treaty, the wording it construes is the standard OECD-model residence article reproduced in the Franco-British treaty, so the reasoning travels: being taxed by both states under their domestic laws is the starting point of the analysis, not its conclusion.
Paragraph 2 then works as a cascade, and the order is mandatory: a later step may only be used where the earlier one fails to produce a single answer. First, the person is deemed resident only of the state where he or she has a permanent home at his or her disposal; where such a home exists in both states, residence goes to the state with which personal and economic links are closest, known as the centre of vital interests. The permanent home, the foyer d’habitation permanent, thus comes first, meaning a dwelling kept continuously available rather than hotel nights or occasional stays. Second, where that centre cannot be determined, or where there is a permanent home in neither state, residence follows habitual abode, the séjour habituel. Third, where habitual abode lies in both states or in neither, nationality decides, which is why nationality is a weak argument at the first step and a decisive one at the third. Fourth, dual nationals and persons holding neither nationality go to agreement between the two administrations, the mutual agreement procedure examined below.
The Conseil d’État applied this exact cascade in its decision of 9 June 2021, no. 431551, and that judgment is the best worked example of how a court walks down the steps. After confirming French domestic domicile, the court turned to the treaty without apology: “c’est sans erreur de droit qu’après avoir jugé que M. A… et Mme D… avaient leur résidence fiscale en France, la cour a examiné si les stipulations de l’article 4 de la convention franco-suisse du 9 septembre 1996 citées au point 4 ci-dessus faisaient obstacle à leur imposition en France.” It then quoted the treaty’s first step: “Cette personne est considérée comme résident de l’Etat contractant où elle dispose d’un foyer d’habitation permanent, cette expression désignant le centre des intérêts vitaux, c’est-à-dire le lieu avec lequel les relations personnelles sont les plus étroites”. On the facts, permanent homes and vital interests pointed both ways despite a Swiss settlement permit, two cars and a Lausanne-owned flat, so step (a) failed; habitual abode could not be determined either, so step (b) failed; and the court therefore applied step (c): “la cour a fait application du c) du 2 de cet article et jugé que M. A… ayant la nationalité française au cours des années en litige, il devait être regardé comme domicilié fiscalement en France. En statuant ainsi, la cour n’a pas commis d’erreur de droit ni dénaturé les pièces du dossier qui lui était soumis.” British readers should read this holding as a mirror. Where a British-only national keeps available homes in both countries, centres interests on both sides and stays habitually in both, the same step (c) designates the United Kingdom, and France must then tax only French-source income. Nationality is a weak argument at step (a) and a decisive one at step (c); files are lost by invoking it too early and won by building the earlier steps methodically.
One warning from the 11 March 2026 ruling of the Cour de cassation, no. 25-10.235 belongs in every dual-residence file. The taxpayers argued that a conflict of residence existed simply because both administrations claimed them, producing a Swiss residence certificate. The court approved the lower court’s answer: “pour pouvoir revendiquer l’application de la convention franco-suisse, M. et Mme [M], considérés par l’administration française comme des contribuables ayant leur domicile fiscal en France au titre des années 2007 et 2008, doivent démontrer non seulement que les autorités suisses leur attribuent la qualité de résident fiscal en Suisse, mais également qu’ils ont cette qualité au sens de cette convention.” A foreign tax certificate is necessary but never sufficient; you must prove residence within the meaning of the treaty itself, step by step. For a Briton facing the DGFiP, an HMRC confirmation of UK residence opens the door to Article 4 but does not walk you through the cascade. The evidence must address each step in order: availability and permanence of each dwelling, the geography of personal and economic links, the pattern of habitual stays, and only then nationality.
Winning the residence question does not end the computation; it redirects it. Where the treaty makes you French-resident, France taxes worldwide income but must relieve double taxation, and the treaty organises that relief by the credit method. Article 24 of the convention provides that French tax levied in accordance with the treaty on French-source income is credited against United Kingdom tax computed on the same taxable profits, income or gains. The United Kingdom gives a credit for the French tax on the same income, so correctly computed double claims should leave only the higher of the two bills, not the sum. Where the treaty makes you British-resident, France taxes only the French-source income listed in domestic law, and a second bill on top of full UK taxation of the same income is, in principle, a treaty breach to be challenged rather than paid twice.
B. Declaring correctly, paying only what the treaty allows, and challenging the rest before the deadlines expire
The first duty is to declare, and declaring does not mean conceding. Article 170 of the General Tax Code states: “En vue de l’établissement de l’impôt sur le revenu, toute personne imposable audit impôt est tenue de souscrire et de faire parvenir à l’administration une déclaration détaillée de ses revenus et bénéfices, de ses charges de famille et des autres éléments nécessaires au calcul de l’impôt sur le revenu”. Every person liable to income tax must file a detailed return of income, household composition and the elements needed to compute the tax. In practice the British household files the standard return, form 2042, with the foreign-income schedule, form 2047, for British-source items, and the treaty position should be stated consistently on the return: worldwide income with credit claimed where France is the treaty residence, or French-source income only where the treaty makes you British-resident. A return that contradicts the treaty position you later defend, for example worldwide income declared without comment by someone claiming British treaty residence, becomes the administration’s first exhibit. File on time, declare everything the form asks for, and make the treaty claim explicit and consistent from the first filing.
The computation that follows depends entirely on which side of Article 4 you land. If the cascade makes you French-resident, French social charges, the prélèvements sociaux, and progressive income tax apply to worldwide income, with the United Kingdom relieving its own tax by credit under Article 24. If the cascade makes you British-resident, France may tax only the categories domestic law reserves for non-residents. Article 164 B of the General Tax Code lists them, starting with: “Sont considérés comme revenus de source française : a. Les revenus d’immeubles sis en France ou de droits relatifs à ces immeubles”. French rental income from your French flat is the textbook example, alongside French business profits and French employment performed in France. And non-residents face a specific minimum machinery: Article 197 A of the same Code provides that “l’impôt ne peut, en ce cas, être inférieur à un montant calculé en appliquant un taux de 20 % à la fraction du revenu net imposable inférieure ou égale à la limite supérieure de la deuxième tranche du barème de l’impôt sur le revenu et un taux de 30 % à la fraction supérieure à cette limite”, while adding the taxpayer’s escape: “lorsque le contribuable justifie que le taux de l’impôt français sur l’ensemble de ses revenus de source française ou étrangère serait inférieur à ces minima, ce taux est applicable à ses revenus de source française.” A British-resident owner of a French letting flat who simply accepts the 20 percent minimum without computing the worldwide average rate routinely overpays; the justification of the lower average rate must be made with documents covering worldwide income, which is precisely the file many owners never assemble.
When the assessment, the avis d’imposition, is wrong, remedies run on three tracks with strict time limits, and the order matters. The domestic track starts with the written claim to the tax office, the réclamation contentieuse. Article R*196-1 of the Tax Procedure Book, the Livre des procédures fiscales, sets the deadline: “Pour être recevables, les réclamations relatives aux impôts autres que les impôts directs locaux et les taxes annexes à ces impôts, doivent être présentées à l’administration au plus tard le 31 décembre de la deuxième année suivant celle” of the collection notice, the payment, or the event grounding the claim. Miss that 31 December of the second following year and the domestic door closes, whatever the merits. If the office rejects the claim expressly or stays silent for six months, the dispute moves to the administrative court, the tribunal administratif, then on appeal to the cour administrative d’appel and, on points of law, to the Conseil d’État whose decisions structure this article. Litigation is slow and public-law flavoured: the judge reviews the bundle of evidence, applies Article 4 B, then the treaty cascade, exactly as the 2021 and 2022 rulings above illustrate.
The second track is the treaty track, and dual-residence cases should almost always open it. Article 26 of the convention, headed procédure amiable, allows a resident of either state who considers that measures taken by one or both states produce taxation contrary to the treaty to present the case to the competent authority of his or her state of residence, independently of domestic remedies. The time limit is three years from the first notification of the offending measure, or six years from the end of the tax year or taxable period concerned, which makes three years from the first notice the headline deadline. The competent authority must then, where the complaint appears founded and cannot be resolved unilaterally, endeavour to settle the case by mutual agreement with the other state’s competent authority. In practice the French competent authority sits within the tax administration’s international division and the British one within HMRC, and the request must present the cascade analysis step by step with exhibits. Filing the mutual agreement request does not suspend the domestic deadline, so protective domestic claims must be filed in parallel; the treaty track complements the court track, it never replaces its calendar.
The third track is evidence, and it is where most British files are won years before any hearing. Build the bundle for each disputed year around the cascade. For step (a), prove which dwellings were continuously available to you and your household: leases or title deeds, council tax bills and taxe d’habitation notices, utility consumption records of the kind the Conseil d’État itself weighed in 2021, and insurance schedules. For the centre of vital interests, map personal life and money separately: where the spouse and children actually lived and went to school, where bank accounts were operated day to day, where directorships and management decisions sat, where the doctor, the clubs and the registered address were. For habitual abode, keep the travel calendar with boarding passes and passport stamps, because day counts that HMRC already holds will be compared with yours. For nationality, keep passports and, where relevant, certificates showing single British nationality. Add the United Kingdom side of the file: the HMRC residence analysis, P85 or self-assessment records of departure, and any HMRC confirmation of residence, remembering the 2026 warning that such a confirmation opens the treaty door without deciding what lies behind it. Assemble this bundle before the first claim letter, because the claim letter, the mutual agreement request and any later court all read the same exhibits, and contradictions between them are fatal.
Three recurring British profiles illustrate how the analysis bites. The retiree who sold the Kent house, rents in the Dordogne and returns to adult children for holidays will usually lose step (a) to France and should focus on correct credit computation rather than denial of French residence. The consultant employed in London, working remotely from a French village house four days a week with a spouse in France, will typically meet both the French professional-activity limb and a British ties test, and the file turns on the centre of vital interests with employment evidence on each side. The owner of a French second home who never settled, spends under ninety days a year in France and works full-time in Britain will normally win the cascade for the United Kingdom but must still declare the French rental income under Article 164 B, compute the Article 197 A minimum against the justified average rate, and challenge any assessment that taxes non-French income. Each profile pays a different bill, and the error to avoid in all three is paying first and arguing later without protective claims inside the deadlines.
Conclusion
Dual tax residence between France and the United Kingdom is not a paradox and not a choice; it is the predictable result of two domestic tests that measure different things, one centred on home, family and economic life, the other on days, homes and ties. The France-United Kingdom treaty resolves the overlap by designating a single residence through the ordered cascade of Article 4: permanent home, then centre of vital interests, then habitual abode, then nationality, then agreement between the administrations. French courts apply that cascade strictly, require treaty residence to be proved within the meaning of the treaty rather than by foreign certificates alone, and punish files that confuse owning a French flat with living in France or confuse holding a British passport with winning the tie-break. The practical discipline follows: declare consistently from the first return, compute under the correct residence outcome with credits or source-only taxation as the treaty directs, file the domestic claim before 31 December of the second following year, open the mutual agreement procedure within three years of the first offending notice, and build the year-by-year evidence bundle before any of those clocks runs out. Done in that order, the household that genuinely lives between two countries pays the higher of the two bills on each item of income, never the sum of both.
Need a quick opinion on your case
A telephone consultation with a lawyer of the firm, within 48 hours: 80 EUR incl. VAT.
Call +33 6 46 60 58 22 or write via our contact page.