You moved from London, Manchester or Edinburgh to Paris, Lyon or the Dordogne after Brexit, you have a visa or a Withdrawal Agreement residence permit in your passport, the removal boxes are unpacked, and then a letter or a neighbour mentions the déclaration des revenus, the yearly French tax return. Every British newcomer meets the same moment of doubt: from which date does France treat me as one of its own taxpayers, which forms do I actually have to file, and how do I stop Her Majesty’s Revenue and Customs and the French tax office both taking a bite of the same pound of income? This guide answers those three questions in the order a newcomer meets them. It explains the French words as they come, because the administration will write to you in French even when your life is still organised in English: the declaration n° 2042 is the main yearly return form, the 2047 is the annexe for income received abroad, and the 3916 is the statement of bank accounts held outside France. The move itself decides everything, so the first part starts with the date your French tax life begins and the residence test the courts apply, then walks through the forms for the arrival year. The second part deals with the double charge that worries every Briton: how the tax treaty signed in London on 19 June 2008 between France and the United Kingdom removes double taxation through a credit mechanism, and why your British current accounts, savings and ISAs must be declared in France even though they stay in Britain. Each step is anchored in the exact statute, the official guidance and recent court decisions, so that a refusal, a reassessment or a penalty can be challenged on solid ground rather than shrugged at.

I. When France starts taxing you: the move date, the domicile test and what goes on the first return

A. Am I a French tax resident from the day I move to France?

French income tax does not know a gentle transition period. Article 4 A of the French General Tax Code (Code général des impôts, the single statute that gathers most French tax rules) draws a hard line: “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” (article 4 A of the General Tax Code). In plain English, once your tax home (domicile fiscal) is in France, France taxes your worldwide income, and before that date it can only tax income arising in France. The practical question for a British arrival is therefore always a date question: on which day did my domicile fiscal move across the Channel?

The answer comes from article 4 B of the same Code, which gives three alternative tests, and meeting any one of them is enough: “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 ;” (article 4 B of the General Tax Code), to which the statute adds “c. Celles qui ont en France le centre de leurs intérêts économiques.” For most British newcomers the first test decides the date: the foyer, the place where you normally live with the centre of your family life, or failing that the place of your main stay (séjour principal). If you arrive with your spouse and children and settle them in a French home, your foyer moves with the family, even if you keep commuting to London for a few months. If you arrive alone for a French job while the family stays in Kent, the second test, professional activity in France, will usually catch you from the first payslip, unless that activity is genuinely secondary.

The courts read these tests factually, file by file, and newcomers should know exactly how strict that reading is. On 11 May 2022 the Conseil d’Etat, France’s supreme administrative court, quashed an appeal ruling about a single man working in Saudi Arabia because the lower court had treated too lightly the definition of the home: “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” (Conseil d’Etat, 9th chamber, 11 May 2022, no. 450692). The lesson is symmetrical and directly useful to a Briton landing at Charles de Gaulle: temporary stays elsewhere do not move your tax home, but the place where you normally live and centre your personal life does, from the moment that centre genuinely shifts. Owning a flat, keeping a bedroom for holidays and paying maintenance to children in France were held, in that same ruling, insufficient on their own to fix the foyer in France, which shows how carefully judges weigh the whole picture rather than ticking one box.

A Paris judgment of 29 April 2025 applies the same logic to a married couple and spells out the family version of the rule: the Paris court defines the home as the place where the taxpayer normally lives with the centre of family interests, ignoring temporary stays elsewhere for work or exceptional reasons, and holds that the main place of stay only decides tax domicile where there is no such home (Paris judicial court, 9th chamber, 1st section, 29 April 2025, RG 22/06549). For a British household this means the administration will look at where the children go to school, where the family doctor and the social life are, and where the couple actually sleeps most nights, not at the address printed on a UK driving licence. Keep the evidence from day one: the lease or completion deed (acte de vente), school enrolment certificates, utility bills and the one-way Eurotunnel or ferry booking all help fix the date if the tax office later argues you arrived earlier or later than you say.

One more layer protects residents of both countries. Where French domestic law and British domestic law each claim you, the treaty signed in London on 19 June 2008 between France and the United Kingdom for the avoidance of double taxation contains tie-breaker rules that allocate residence to one state only, and the French tax office publishes its official commentary on that treaty in the BOFiP, the public tax doctrine database (France-United Kingdom tax treaties, BOFiP). The consolidated treaty text is published by the French tax administration (France-United Kingdom convention as amended, impots.gouv.fr) and was given the force of law in France by decree no. 2010-20 of 7 January 2010, so it overrides the domestic tests where they conflict. In practice a newcomer rarely needs the tie-breaker in year one, because the move is usually clean, but anyone keeping a genuine home, spouse or centre of business in Britain while settling in France should read those tie-breaker criteria before filing, since getting residence wrong in the first return poisons every later year. Readers who are still sorting out their right to live in France at all should start with our guide to first residence permits, renewals and refusals after Brexit, because tax residence without a secure immigration status is a house built on sand.

B. Which income goes on the first return, and on which forms?

The arrival year is a split year in substance even though France sends you a single tax notice. Income received before the move, while your tax home was still British, stays outside the French return unless it is French-source income; income received after the move goes in, worldwide. Article 170 of the General Tax Code states the filing duty bluntly: “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” (article 170 of the General Tax Code). For the newcomer this means listing, for the period running from the arrival date to 31 December, every salary, pension, rental receipt, dividend and capital gain, wherever in the world it was paid, and converting sterling amounts into euros at the rate applicable on receipt.

The official impots.gouv.fr guidance for people arriving in France confirms the mechanics step by step. In the spring of the year following arrival (year N+1 for an arrival in year N), you declare online or, failing that, on paper by sending return no. 2042 to the tax office for individuals (Service des impôts des particuliers) of your new French address, covering all income received between the arrival date and 31 December, plus the relevant annexes such as the 2044 for rental income and the 2047 for income collected abroad (arriving in France: how and what to declare, impots.gouv.fr). The same guidance carries a warning newcomers constantly miss: first-time filers have no access to online filing and must complete a paper return. The very first French return is therefore filed on paper, because the online personal account (espace particulier) only opens once the administration has created your tax file. File that paper return by the deadline, keep proof of posting, and the online account follows for later years; the general first-declaration page adds that the withholding at source (prélèvement à la source) changes nothing about the yearly filing duty (first declaration guide, impots.gouv.fr).

Two traps sit on either side of the arrival date and both cost money. Before the move, France could still tax you as a non-resident on French-source income, and article 164 B of the General Tax Code lists what counts: “Sont considérés comme revenus de source française : a. Les revenus d’immeubles sis en France ou de droits relatifs à ces immeubles ; b. Les revenus de valeurs mobilières françaises et de tous autres capitaux mobiliers placés en France ; c. Les revenus d’exploitations sises en France ; d. Les revenus tirés d’activités professionnelles, salariées ou non, exercées en France ou d’opérations de caractère lucratif au sens de l’ article 92 et réalisées en France” (article 164 B of the General Tax Code). A Briton who owned a Dordogne holiday home and let it furnished while still living in Leeds, or who did paid consultancy days in Paris before relocating, had French taxable income well before the removal van. Non-residents in that position face a minimum charge that surprises many: “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” (article 197 A of the General Tax Code). After the move, the mirror trap is forgetting that residence makes worldwide income declarable, including the UK salary for the months already worked, the UK rental profit and the interest on British savings. Declare the pre-arrival French income under the non-resident rules and the post-arrival worldwide income on the 2042 with the 2047 annexe, and the two periods join cleanly; mix them up and the administration reassesses with late-payment interest and penalties.

Paris and Ile-de-France newcomers face the same national rules but deal with the largest tax offices in the country, and files move faster when they land on the right desk from the start. The paper first return goes to the Service des impôts des particuliers of the new domicile, so a family settling in the 15th arrondissement writes to Paris, not to the non-residents office that handled any earlier French rental income, while reassessments in the capital are pursued by the Paris regional tax directorate (Direction régionale des finances publiques d’Ile-de-France et de Paris), the very office that appears as defendant in the Paris residence disputes cited above. Anyone arriving in Paris with a complex file, share options vesting across the move, a UK property sold in the arrival year or a pension lump sum, should diary two dates now: the spring filing deadline for the N+1 return and the 31 December cut-off that closes the arrival period. Our companion guide to British pensions taxed in France, treaty rules and QROPS transfers takes over where this section stops, because pension income is the item most newcomers declare worst in year one.

II. Paying tax once, not twice: the Franco-British treaty credit and the accounts you must declare

A. How do I stop the same income being taxed in London and Paris?

The fear every British newcomer voices in the first meeting is simple: Britain taxes me on the way out, France taxes me on the way in, and the same salary or dividend pays twice. The treaty signed in London on 19 June 2008 exists precisely to prevent that, and its method for France is not exemption but credit: France keeps the income in its tax base, calculates French tax on it, then wipes out the French charge up to the treaty limit. Article 24 of the treaty, on eliminating double taxation, provides that “nonobstant toute autre disposition de la présente Convention, les revenus qui sont imposables ou ne sont imposables qu’au Royaume-Uni conformément aux dispositions de la présente Convention sont pris en compte pour le calcul de l’impôt français”, adding that UK tax is not deductible but that “le résident de France a droit, sous réserve des conditions et limites prévues aux alinéas (i) et (ii) et au paragraphe 4, à un crédit d’impôt imputable sur l’impôt français”, a credit equal “(i) pour les revenus non mentionnés à l’alinéa (ii), au montant de l’impôt français correspondant à ces revenus à condition que le résident de France soit soumis à l’impôt du Royaume-Uni à raison de ces revenus” (convention of 19 June 2008, article 24, paragraph 3, cited in Conseil d’Etat avis of 12 February 2020, no. 435907). Three consequences follow that newcomers constantly get wrong. First, the income must still be declared in France even when the treaty gives the primary taxing right to Britain; undeclared means untaxed, and the credit never arises on income the return hides. Second, the ordinary credit under subparagraph (i) equals the French tax on that income, so where Britain taxed lightly the credit only cancels French tax up to its own amount and any surplus British charge is simply lost. Third, the credit is conditional on genuinely being liable to UK tax on the same income, which is why keeping HMRC assessments, P60s and dividend vouchers for the arrival year is as important as keeping French payslips.

The Conseil d’Etat’s 2020 advisory opinion on this very treaty repays close reading, because it settles two points that protect French residents with British income. On the opening words of the article, the court holds that “l’expression ” nonobstant toute autre disposition de la présente Convention ” qui figure à la première phrase de ce paragraphe, signifie qu’alors même que d’autres stipulations de la convention prévoient que certains revenus sont imposables ou ne sont imposables qu’au Royaume Uni, ces revenus peuvent néanmoins être pris en compte pour le calcul de l’impôt français”, before adding the shield that matters for social charges: “L’expression en cause ne saurait permettre à la France, s’agissant des résidents de France personnes physiques, de ne pas appliquer le crédit d’impôt prévu à l’alinéa (i) du a) du paragraphe 3 de l’article 24 aux contributions sociales françaises, au motif qu’aucun impôt sur le revenu ou sur un élément du revenu de nature équivalente n’existe au Royaume-Uni” (Conseil d’Etat avis, 12 February 2020, no. 435907). In everyday terms, the French social contributions (contributions sociales: the CSG, the generalised social contribution, and the CRDS, the debt-repayment contribution, which the treaty lists among the French taxes it covers) on British-source income attract the treaty credit too, and the administration cannot refuse it merely because Britain has no equivalent of the CSG. That holding alone has saved many newcomer files from a second layer of French charge on UK dividends and rental profits.

In practice the credit runs through form 2047, the annexe for foreign income, which feeds the 2042 and computes the crédit d’impôt égal à l’impôt français, the credit equal to the French tax. Report each category of British income gross, indicate the treaty article that allocates it, attach the British proof of taxation, and check that the notice of assessment (avis d’imposition) shows the credit line before paying anything. Where the treaty instead gives France the exclusive right, typically French rental income kept after the move or a French employment, no credit enters the picture and France simply taxes; where it gives Britain an exclusive right with progression, France exempts but keeps the income in the rate calculation (taux effectif, the effective-rate rule that pushes the rest of the income into a higher band). The mirror question on the British side, when HMRC still treats you as UK-resident for part of the year and how split-year treatment interacts with the French claim, belongs to British advisers, and the British government’s own starting point for expatriates remains its Living in France guidance. State and private pensions deserve their own map because treaty article 18 and the lump-sum rules twist the standard credit path, which is why our detailed pensions guide for Britons in France should be read alongside this section before anyone triggers a UK pension payment in the arrival year.

B. Do I really have to declare every British bank account to France?

Yes, and this is the obligation British newcomers breach most often, usually out of loyalty to a lifelong current account rather than any wish to hide money. Article 1649 A of the General Tax Code provides that individuals domiciled or established in France “sont tenues de déclarer, en même temps que leur déclaration de revenus ou de résultats, les références des comptes ouverts, détenus, utilisés ou clos à l’étranger” (article 1649 A of the General Tax Code). Form 3916, the foreign-account statement, is filed with the first return and every later one, and it covers everything: the Halifax or Barclays current account kept for direct debits, the savings account, the stocks-and-shares ISA, the premium bonds arrangement where an account reference exists, and any account closed during the year, since closure does not erase the duty for the year of closure. Joint accounts are declared by each holder, and accounts on which you hold only a signing authority for an elderly parent or a family company are declarable just the same. The only accounts outside the rule are those the statute and the implementing guidance expressly leave out, and a British newcomer should never assume an account qualifies for an exception without checking the current BOFiP commentary first.

The sting is not theoretical. The Code attaches the same paragraph a presumption that turns silence into taxable income: “Les sommes, titres ou valeurs transférés à l’étranger ou en provenance de l’étranger par l’intermédiaire de comptes non déclarés dans les conditions prévues au deuxième alinéa constituent, sauf preuve contraire, des revenus imposables” (article 1649 A of the General Tax Code). A transfer through an undeclared British account is therefore treated as taxable income unless the taxpayer proves otherwise, which reverses the normal burden and makes every unexplained movement into evidence for the administration. Alongside that presumption, failure to file the 3916 exposes the taxpayer to a fine per undeclared account under article 1736 of the General Tax Code, and the two sanctions stack: the fine punishes the missing form while the reassessment taxes the money. Newcomers sometimes ask whether small balances or dormant accounts escape notice now that the Anglo-French automatic exchange of financial information sends HMRC data to Paris every year; the honest answer is that the exchange makes discovery more likely with each passing year, while voluntary correction of the first return, through a corrective return (déclaration rectificative) filed as soon as the omission is spotted, always costs less than a reassessment built on exchanged data.

Organisation beats anxiety here, and the arrival year is the moment to build the file that will serve for the whole French tax life. List every British account with its bank, sort code, account number, opening date and highest balance; download a full year of statements before online access tied to a UK mobile number goes cold; note which accounts fund which declared income so the 2047, the 3916 and the bank movements tell one consistent story. Where the estate behind the accounts is larger, a French house bought with British savings, children in two countries, or a spouse who stayed UK-resident, the succession dimension should be settled in the same year, and our guide to choosing English law for a French house and protecting the children explains the will and forced-heirship rules that the tax return never shows. Done properly, the first return becomes what it should be: the foundation stone of a clean French tax record, with every account declared, every credit claimed and every date provable.

Conclusion

The first French tax return of a British newcomer stands on three pillars, and each of them is verifiable before anything is filed. The residence date follows the foyer test of article 4 B as the courts read it, worldwide income from that date goes on the paper 2042 with the 2047 annexe, and British-taxed income comes back through the treaty credit of article 24 as the Conseil d’Etat construes it, while every British account goes on the 3916 under article 1649 A. Miss the date and the wrong year’s income enters the base; skip the 2047 lines and the credit never materialises; forget the 3916 and transfers become presumed income plus fines. None of these outcomes is fate: each follows mechanically from the return as filed, which means each can still be corrected by a taxpayer who understands the mechanism. File the arrival year carefully, keep the British proofs beside the French forms, and the second return, online this time, will feel like routine instead of a second crossing of the Channel.