You have just swapped the United Kingdom for France after Brexit: the removal boxes are barely unpacked, your children may already be enrolled at the local school, and your current accounts, savings and pension are still sitting with a British bank. Then, in the spring after the year of your arrival, France hands you a task few newcomers expect: a first French income tax return covering your worldwide income, plus a separate declaration for every bank account you still hold abroad. Miss the second form and each undeclared UK account can cost you a fixed fine of 1,500 euros, even if the account earned almost nothing. This guide explains, step by step, when France treats you as tax resident from the day you arrive, which forms to file for your UK pensions, rents and savings, how the France-UK double tax treaty of 19 June 2008 shares the tax bill between the two countries, and which remedies exist when the French tax office sends a bill or a penalty you consider wrong. Every decisive rule below is quoted word for word from the statute, the treaty or a court decision, with an official link so you can check it yourself.

I. You have just moved to France from the UK: when France taxes your worldwide income and which forms to file

A. Are you French tax resident from the day you arrive? The foyer test and the arrival-year return

French tax residence does not wait for a card, a visa stamp or a full calendar year. Article 4 A of the French General Tax Code (Code général des impôts, the main French tax statute) states:

“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, Code général des impôts)

In plain English: once your tax home (domicile fiscal) is in France, France taxes all of your income from everywhere; before that, it taxes only your French-source income. The decisive question is therefore the day your tax home moves, and Article 4 B of the same code gives three alternative tests, of which a single one 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 ; […] c. Celles qui ont en France le centre de leurs intérêts économiques.” (Article 4 B, Code général des impôts)

For a British family settling in France, the first test usually decides everything. The foyer means the place where you habitually and permanently live with your family; the lieu du séjour principal means the place where you spend most of your time. If your spouse and children live in Lyon while you keep flying back to London for work, the tax office will argue that your foyer is in France even if you personally spend long weeks in Britain. If you live alone and split the year between a flat in Paris and a house in Kent, the office counts the days and looks at where your daily life is actually centred. The professional-activity test is a useful backstop for the administration: taking a French job, even part-time, points toward French residence unless you can show the French work is merely secondary. The economic-interests test covers the person whose money life is centred in France, with investments, property and income streams managed from here.

Note the final sentence of the first paragraph of Article 4 B, which many newcomers overlook: a person who meets one of these tests still cannot be treated as French tax resident where an international double-tax treaty regards that person as resident elsewhere. The treaty can therefore correct the domestic answer, but only after domestic residence has been established in both countries. The Cour de cassation, the highest French civil court, enforces this order strictly: domestic law first, treaty tie-breaker second. In a 2021 decision on a Franco-Swiss residence conflict, it recalled that the treaty defines “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.” (Cour de cassation, Chambre commerciale, financière et économique, 24 November 2021, pourvoi n° 19-14.013) The method is identical under the France-UK treaty, as Part I.B shows.

Once French residence is established, the filing duty follows automatically. Article 170 of the General Tax Code provides:

“1. 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, Code général des impôts)

The same article adds a sentence written for your exact situation: persons domiciled or fiscally domiciled in France who receive from abroad, directly or through an intermediary, income of the kind listed in Article 120 of the code must include that income in the return. Article 120 covers, among other things, dividends, interest and similar products of foreign shares and holdings:

“Sont considérés comme revenus au sens du présent article : 1° Les dividendes, intérêts, arrérages et tous autres produits des actions de toute nature et des parts de fondateur des sociétés, compagnies ou entreprises financières, industrielles, commerciales, civiles et généralement quelconques dont le siège social est situé à l’étranger quelle que soit l’époque de leur création ; […]” (Article 120, Code général des impôts)

In practice, the French tax administration tells newcomers exactly what to do in the arrival year. The official impots.gouv.fr guidance for people arriving in France states:

In the spring of the year after arrival (year N+1), newcomers must file online or, failing that, on paper form 2042 sent to the tax office of their new French home. (impots.gouv.fr, Je viens ou je reviens en France)

Form 2042 is the main French income tax return (déclaration d’ensemble des revenus). You declare the income received between the date of your arrival and 31 December of year N, and you attach the relevant schedules: form 2047 for income collected abroad (revenus encaissés à l’étranger), form 2044 for rental income from property (revenus fonciers), and form 3916 for foreign bank accounts. The same guidance adds: The return must cover all income received between the arrival date and 31 December of year N, with the relevant schedules added according to the income types, such as form 2044 for property income and form 2047 for income collected abroad. French-source income received before your arrival, from 1 January to the date of return, goes on a separate non-resident return, form 2042-NR. France therefore has no equivalent of the British split-year relief that divides one tax year into a UK part and an overseas part; it runs two returns instead, one for each status period.

On the British side, tell HM Revenue and Customs that you have left. The official GOV.UK guidance explains: form P85, or the equivalent online claim, is the channel for telling HMRC about the departure and claiming UK employment-tax relief or repayment. (GOV.UK, Get your Income Tax right if you are leaving the UK (P85)) Filing the P85 does not by itself end your French obligations, and it does not decide your French residence either; it simply puts your British tax record straight for the departure year while France applies its own tests from the day you settle here.

B. How to declare your UK pension, rental income and savings on form 2047 and get treaty relief

Form 2047 is the schedule where French residents report income collected outside France. Each category of British income follows its own treaty rule, but the architecture is always the same: declare everything in France first, then claim the relief the treaty grants, with a credit or an exemption depending on the type of income. The three categories that cause British newcomers the most trouble are pensions, rental income and investment income.

British pensions must be declared in France once you are French tax resident, even when the pension continues to be paid from London. The treaty allocates the right to tax pensions between the two States according to their nature: most private and occupational pensions are taxable only in the State of residence, while government service pensions, the British crown pensions paid for past employment in the civil service, the armed forces, the police or local government, generally remain taxable only in the United Kingdom. The well-known 25 per cent tax-exempt lump sum (pension commencement lump sum) that is exempt from British tax is not automatically exempt from French tax, because France applies its own qualification to the payment. If you received such a lump sum shortly before or after the move, declare it and let the treaty article on pensions decide the outcome rather than assuming the British label travels with the money. Readers who want the full pension picture can consult our detailed guide to British pensions taxed in France, the 25 per cent lump sum and crown pensions.

Rental income from a house or flat you kept in Britain must be reported on the French return, with the British rent entered on form 2047 and then carried to the property-income sections of the main return. The treaty allows the United Kingdom, as the State where the property stands, to tax that rent, and France, as your State of residence, eliminates the resulting double taxation through a tax credit. The mechanism is described in Article 24 of the France-UK treaty, which deals with the elimination of double taxation. For France, the rule reads:

Under Article 24(3)(a), France takes income taxable or taxable only in the United Kingdom into account to compute the French tax, refuses any deduction of the British tax from that income, and grants the French resident a tax credit against French tax, subject to the conditions and limits stated in the following subparagraphs ( France-UK double tax treaty of 19 June 2008, official consolidated version on impots.gouv.fr)

In practice this means the British rent increases your French taxable base, so it pushes up the rate applied to your other income, but France then subtracts a credit equal to the French tax on that rent, provided you were actually taxed in Britain on it. Keep the British tax assessments and letting accounts: the French office routinely asks for proof that the British tax was charged before it grants the credit. Our companion article on British landlords taxed in France on UK rental income walks through forms 2047 and 2042 for that exact profile.

Interest, dividends and similar savings income from British accounts and shares are declared the same way, with the treaty generally capping the British withholding tax, commonly at 15 per cent for small individual shareholders, and France granting a credit for the British tax within the limit of the French tax on the same income. Report the gross amounts before any British withholding, then claim the credit; reporting only the net payment received is one of the most common newcomer mistakes and it guarantees a reassessment.

Where both countries claim you as their resident in the arrival year, which happens often when you keep a British home while renting or buying in France, Article 4 of the treaty settles the conflict with a tie-breaker applied in strict order. The official treaty text provides:

Article 4(2) then settles dual residence in a strict cascade: the permanent home comes first; a person with a permanent home in both States is deemed resident only where personal and economic ties are closest, the centre of vital interests; then comes the State of habitual presence; then the State of nationality; and finally, mutual agreement between the two tax authorities ( France-UK double tax treaty of 19 June 2008, official consolidated version on impots.gouv.fr)

The order matters enormously. The permanent home (foyer d’habitation permanent) comes first: a house you own and continuously occupy in France against a rented room kept in London points to France. Only if you hold a permanent home in both States does the analysis move to the centre of vital interests, the place with which your personal and economic ties are closest. Habitual presence comes third, nationality fourth, and a mutual agreement between the two tax authorities last. British nationality alone therefore never decides the issue while an earlier test gives an answer, which surprises many newcomers who assume their passport protects them.

The Cour de cassation treats this sequence as mandatory. In the 2021 residence-conflict decision cited above, both the French and the foreign tax administrations regarded the taxpayers as their own residents, and the court held that this dual claim created a residence conflict requiring the treaty’s tie-breaker: “ce dont il résulte l’existence d’un conflit de résidence fiscale commandant qu’il soit fait application de l’article 4, paragraphe 2, de la convention”, so that the appeal court which had refused to run the tie-breaker analysis had “violé les textes susvisés” (Cour de cassation, Chambre commerciale, financière et économique, 24 November 2021, pourvoi n° 19-14.013, cassation and remand). For a British newcomer, the practical lesson is to build the file in the treaty’s order from day one: deeds or leases proving where the permanent home is, school and medical records showing where family life happens, employment contracts and board minutes showing where work is directed, travel records showing habitual presence, and finally nationality documents. If HMRC issues a certificate of UK residence for treaty purposes, keep it, but remember the French judge makes a sovereign assessment and is not bound by the foreign administration’s view. Readers facing a genuine dual-residence claim should read our full analysis of the Franco-British tie-breaker that decides dual tax residence.

II. The form 3916 trap and the penalty machine: foreign accounts, fines and how to fight back

A. Every UK current account must be declared: what counts as used and what the fine really is

The shock most British newcomers describe goes like this: the income return was filed correctly, the treaty credit was claimed, and months later a separate penalty arrives for the humble British current account used to pay the old mortgage, the council tax on the unsold house or the children’s school fees. The penalty comes from a separate duty that sits alongside the income return. Article 1649 A of the General Tax Code provides:

“Les personnes physiques, les associations, les sociétés n’ayant pas la forme commerciale, domiciliées ou établies en 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, Code général des impôts)

Four words do all the damage: opened, held, used or closed. An account counts if it meets any one of them during the year, so the dormant savings account with 200 pounds in it, the joint account with your spouse, the account for which you merely hold a power of attorney (procuration), and the account you closed in March all have to be listed on form 3916, one form per account, attached to the yearly return. The official English-language guidance on service-public.fr confirms the scope: any account that was open, held, used or closed during the tax year and is domiciled outside France, whether with a bank or any other financial provider such as a broker or notary, must be reported. It adds a practical test for online banks: for online banks, the IBAN decides: anything not starting with FR counts as a foreign account and must be reported every year. (service-public.fr, Do foreign accounts have to be declared?) A narrow exemption exists for small e-commerce collection accounts meeting three cumulative conditions, including total receipts of no more than 10,000 euros in the year and a link to an account already held in France, but an ordinary British current account never fits that exception.

The Cour de cassation has given the word “used” a precise and demanding meaning that helps honest filers as much as it warns careless ones. In a 2021 decision concerning undeclared Swiss accounts, the court approved the rule that “un compte bancaire est réputé avoir été utilisé dès lors qu’il y a été effectué au moins une opération de crédit ou de débit pendant la période visée par la déclaration, que ce soit par le titulaire du compte ou par une personne ayant procuration.” It immediately added the two exceptions: “Ne constituent pas de telles opérations, d’une part, des opérations de crédit qui se bornent à inscrire sur le compte les intérêts produits par les sommes déjà déposées au titre des années précédentes, et, d’autre part, des opérations de débit correspondant au paiement des frais de gestion pour la tenue du compte.” (Cour de cassation, Chambre commerciale, financière et économique, 14 April 2021, pourvoi n° 19-23.230, rejection of the appeal) So a single transfer in or out, by you or by anyone holding your authority, makes the account reportable, while interest credited automatically and bank charges debited automatically do not count on their own. Do not read this as comfort: almost every real-life British account shows at least one genuine movement per year, from a direct debit to a transfer, and the administration obtains account data automatically through the international exchange of information anyway.

The fines are fixed per account and they multiply fast. The same official guidance states: a fixed fine of 1,500 euros per undeclared account, raised to 10,000 euros per account where the account sits in a State that has no tax-evasion assistance convention with France, plus an an 80 per cent increase on the duties on the amounts shown on the undeclared accounts, which then replaces the fixed fine. (service-public.fr, Do foreign accounts have to be declared?) Because France and the United Kingdom are bound by assistance and anti-evasion conventions, the ordinary rate for a British account is 1,500 euros per account, not 10,000. Three forgotten accounts therefore mean 4,500 euros before any tax is even discussed, and where the undeclared account concealed taxable income, the 80 per cent increase on the duties replaces the fixed fine and dwarfs it. These fines sit on top of the ordinary late-filing penalties for the income return itself. Article 1728 of the General Tax Code provides that missing the filing deadline triggers “une majoration de : a. 10 % en l’absence de mise en demeure ou en cas de dépôt de la déclaration ou de l’acte dans les trente jours suivant la réception d’une mise en demeure d’avoir à le produire dans ce délai ; b. 40 % lorsque la déclaration ou l’acte n’a pas été déposé dans les trente jours suivant la réception d’une mise en demeure d’avoir à le produire dans ce délai” (Article 1728, Code général des impôts), and Article 1758 A adds a specific 10 per cent increase where a late, missing or inaccurate income return reduces the tax due or inflates a refund claim: “Le retard ou le défaut de souscription des déclarations qui doivent être déposées en vue de l’établissement de l’impôt sur le revenu ainsi que les inexactitudes ou les omissions relevées dans ces déclarations, qui ont pour effet de minorer l’impôt dû par le contribuable ou de majorer une créance à son profit, donnent lieu au versement d’une majoration égale à 10 % des droits mis à la charge du contribuable ou de la créance indue.” (Article 1758 A, Code général des impôts) Both increases expressly reward taxpayers who correct their position quickly, which leads directly to the remedies.

B. How to challenge a French tax bill or penalty: correction, formal complaint and the court route

Speed is your best ally. Both penalty regimes reward the taxpayer who fixes the mistake before the administration locks its position. Article 1758 A states that its 10 per cent increase does not apply “Lorsque le contribuable a corrigé sa déclaration spontanément ou dans un délai de trente jours à la suite d’une demande de l’administration” (Article 1758 A, Code général des impôts), and Article 1728 keeps its lowest 10 per cent band for returns filed without a formal demand or within thirty days of one. If you realise in October that your spring return omitted a Leeds building-society account, file a corrective return and the missing form 3916 at once through your online personal space on impots.gouv.fr or at the tax office of your home (Service des impôts des particuliers). A spontaneous correction made before any audit notice will often reduce or remove the income-return increase, though the fixed per-account fine for the missing 3916 can still be charged, which is why the correction letter should expressly request leniency and explain the newcomer context, the Brexit move and the absence of any concealed income.

When the assessment or the penalty has already been issued and you consider it wrong, the standard remedy is the réclamation contentieuse, the formal complaint to the tax administration. Article R*196-1 of the Tax Procedures Book (Livre des procédures fiscales) sets a strict and unforgiving 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, selon le cas : a) De la mise en recouvrement du rôle ou de la notification d’un avis de mise en recouvrement ; b) Du versement de l’impôt contesté lorsque cet impôt n’a pas donné lieu à l’établissement d’un rôle ou à la notification d’un avis de mise en recouvrement ; […]” (Article R*196-1, Livre des procédures fiscales)

In practice, for income tax assessed on a yearly roll, you have until 31 December of the second year after the year the bill was issued. File the complaint online from your impots.gouv.fr personal space, which generates a dated receipt, or by recorded letter to the office shown on the assessment. State precisely what you contest: the treaty credit refused, the residence analysis, the per-account fine, or the 80 per cent increase, and attach the evidence in the order the treaty and the statutes use it. For a refused treaty credit, attach the British assessments proving the British tax was actually charged on the same income, because Article 24 of the treaty conditions the French credit on that charge. For a residence dispute, build the file in the Article 4 order described in Part I.B: permanent home, vital interests, habitual presence, nationality. For a 3916 fine, show the statements proving the account’s nature, argue proportionally where several accounts belong to one household change of residence, and point to the automatic-exchange context rather than concealment where that is the truth.

If the administration rejects the complaint expressly or stays silent for six months, which counts as an implied rejection, you can take the dispute to the administrative court (tribunal administratif) of your place of residence, generally within two months of the rejection. Ask your lawyer whether a simultaneous request for a payment stay or a settlement discussion is appropriate, because court proceedings in tax matters routinely last over a year and interest continues to run in the meantime. One practical Paris point: newcomers who settle in Paris and the inner suburbs deal with some of the busiest tax offices in France, where treaty-credit files and 3916 penalties are processed in high volumes and standardised language. A complaint that quotes the exact treaty paragraph, names the exact form and line, and attaches numbered exhibits in treaty order is read faster and answered more carefully than a general letter of protest. Keep every assessment, every 3916 receipt and every HMRC document for at least the full reassessment period, and never ignore a mise en demeure: the thirty-day window after a formal demand is the last moment to file at the 10 per cent rate before the 40 per cent rate applies.

Conclusion

Your first French tax year as a British newcomer rests on three reflexes. First, accept that France taxes your worldwide income from the day your home moves here, file form 2042 with schedule 2047 for everything collected in Britain, and run the arrival-year mechanics of forms 2042 and 2042-NR exactly as the official guidance describes. Second, treat every British account as reportable on form 3916, because a single genuine movement makes it used in the eyes of the Cour de cassation, and budget 1,500 euros of fixed fine per forgotten account even where no tax was evaded. Third, use the France-UK treaty of 19 June 2008 as the shield it is: Article 4 settles residence conflicts in a strict order that puts your permanent home before your passport, and Article 24 converts British tax actually paid into French credit. And when the bill or the penalty still looks wrong, correct spontaneously, complain before 31 December of the second year, and take the ordered file to the administrative court if needed. The system is demanding but legible, and a newcomer file built in treaty order from the first return is the strongest position from which to challenge anything that follows.

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