You live in France, your children go to school in France, and every morning you open a laptop at a desk in France — yet your payslip comes from London, your tax is deducted under PAYE in Britain, and your employer has never heard of URSSAF, the French body that collects social security contributions. Since Brexit turned British citizens into third-country nationals, this everyday arrangement has become a legal trap with two jaws. The French tax office can treat you as French tax resident from the year you settle and tax your London salary in France, while URSSAF can order your London employer to register in France and pay French employer and employee contributions on that same salary, with surcharges for late registration. Neither bill is cancelled by the fact that you already paid tax or National Insurance in Britain. Relief exists, but it has to be claimed through the right forms, in the right order, with the right papers. This guide explains where you really owe income tax and social contributions when you work remotely in France for a UK employer, what your employer must do even without an office in France, and how to challenge a tax demand or an URSSAF reassessment with evidence that wins.
I. I live in France and work remotely for a UK employer — where do I pay tax and social security?
A. Am I French tax resident when my home, my family and my laptop are all in France?
Start with the French definition of tax residence, because it decides almost everything else. Your domicile fiscal, meaning your tax home, is governed by Articles 4 A and 4 B of the French General Tax Code. Article 4 A 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.” (Article 4 A of the General Tax Code) In plain English, once France regards you as tax resident, you are liable to French income tax on all of your income worldwide, including a salary paid from London. People whose tax home is outside France are liable only on French-source income. So the whole dispute usually turns on Article 4 B, and you can read it in full on Article 4 B of the General Tax Code. It provides: “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 ;” It then adds a third case: “c. Celles qui ont en France le centre de leurs intérêts économiques.”
Three features of that text matter for a British remote worker. First, the three tests are alternatives. Meeting any one of them is enough: your foyer, your family home, in France; your main place of stay in France; or a professional activity carried on in France. Second, working full-time from your French home for a London employer is a professional activity carried on in France. The escape clause for an activity carried on merely on the side (exercée à titre accessoire) does not cover a full-time remote job performed day after day at a French desk. Occasional answers to e-mails while on holiday are one thing; a permanent home office is another. Third, the closing sentence of Article 4 B sends you to the tax treaty: people who meet one of the domestic tests are nevertheless not treated as French tax residents when an international double-tax treaty regards them as resident elsewhere. That is where the France–United Kingdom convention signed on 19 June 2008 comes in, and its official English text is published on the 2008 UK–France double taxation convention.
Article 4 of that convention first confirms that each country applies its own residence rules, then settles dual residence with a tie-breaker applied step by step. The decisive first step deems the person resident only where they have a permanent home available, and where such a home exists in both States, only where their personal and economic relations are closer, known as the centre of vital interests. Only if that test fails to decide does the treaty move to habitual abode, then nationality, then agreement between the authorities. For a British employee whose spouse and children live with them in Lyon, Bordeaux or Paris, who rents or owns only there, and whose daily life is organised around France, the centre of vital interests will normally point to France even if they kept a room at a relative’s house in Kent. Keeping a British bank account or a GP registration does not outweigh a settled family home and full-time work performed in France. The practical consequence is blunt: most British remote workers living year-round in France are French tax resident, liable on worldwide income, and must file a French return declaring the London salary. Even before residence is settled, Article 164 B of the General Tax Code treats as French-source income “Les revenus tirés d’activités professionnelles, salariées ou non, exercées en France”, which you can check on Article 164 B of the General Tax Code. Work physically done in France is therefore within the reach of the French tax office one way or another.
What should you do in practice? File every year. Report the gross London salary on the foreign-income return that accompanies the main French return, convert pounds into euros at the official annual rate, attach the British P60 end-of-year certificate and monthly payslips, and claim treaty relief so the same pounds are not taxed twice in full. Keep your employment contract showing the place of work, travel records proving where you actually sat during the year, and any evidence of family settlement such as school certificates and the French housing lease or title deeds. These papers decide both residence and the amount of relief, and the tax office will ask for them before it moves a figure.
B. Can France really tax the salary my British employer pays me in pounds under PAYE?
Yes, and the reason lies in Article 15 of the 2008 convention, headed income from employment. Its first paragraph gives the residence State the sole right to tax salaries and similar employment income, unless the employment is exercised in the other State, in which case that other State may tax the income arising there. Read that slowly. The starting rule gives the residence country the sole right to tax, but the exception takes over as soon as the work is physically performed in the other country. A French resident whose employment is exercised in France falls squarely under the exception: France may tax the salary attributable to the days worked in France. British PAYE deducted in London does not remove that French right; it only opens the door to relief against double taxation.
Many employees then invoke the 183-day rule, but it rarely helps a settled remote worker. Paragraph 2 of Article 15 preserves exclusive residence-State taxation only where three cumulative conditions hold: presence in the other State for no more than 183 days in any twelve-month period, payment by or on behalf of an employer not resident in that other State, and no bearing of the cost by a permanent establishment the employer has there. A British employee living in France and working daily from a French home is present in France well beyond 183 days and exercises the employment in France, so the exception fails at the first hurdle. The three conditions are cumulative, which means failing one is enough to lose the protection. Short business trips to London do not change the analysis either: treaty practice apportions salary day by day, so the France-worked days stay taxable in France while genuine London-worked days may remain taxable only in Britain. Keep a contemporaneous diary of workdays per country, backed by Eurostar tickets, boarding passes and calendar entries, because the burden of proving the split falls on you.
Two misunderstandings cause most of the damage seen in files. The first is believing that British payroll deductions settle the matter. They do not. France taxes first on its share and then grants relief for the British tax attributable to the same income under the treaty’s elimination-of-double-taxation article, which operates as a credit, not as an exemption. If no relief is claimed on the French return, France simply taxes in full and the British tax already paid is wasted. The second misunderstanding is believing that an employer without a French office means no French tax. The employer’s presence matters for the third condition of the 183-day test and for business-profits questions, but it does not move the employee’s keyboard: the salary follows the place where the work is done. Directors of British companies working from France face an additional twist, because directors’ fees fall under a different treaty article from ordinary salary, so the board minutes, the service contract and the exact label of each payment must be checked before filing. When in doubt, file on the basis that France taxes the French-worked days, claim the credit with full documentation, and keep the P60, the P45 if you changed jobs, and every payslip for at least the whole reassessment period.
II. My UK employer has no office in France — who registers, who pays, and how do I challenge the bill?
A. Must my London employer register with URSSAF and pay French contributions on my salary?
As a rule, yes. French social security follows the place of work, not the nationality of the employee nor the address on the employer’s letterhead. Article L. 311-2 of the Social Security Code states: “Sont affiliées obligatoirement aux assurances sociales du régime général, quel que soit leur âge et même si elles sont titulaires d’une pension, toutes les personnes quelle que soit leur nationalité, de l’un ou de l’autre sexe, salariées ou travaillant à quelque titre ou en quelque lieu que ce soit, pour un ou plusieurs employeurs et quels que soient le montant et la nature de leur rémunération, la forme, la nature ou la validité de leur contrat ou la nature de leur statut.” You can verify the wording on Article L. 311-2 of the Social Security Code. Working at whatever place (en quelque lieu que ce soit) the employee happens to be, for example from a spare bedroom in the Dordogne for a company seated in Manchester is still salaried work performed in France, and it pulls the employee into the French general scheme. Remote work changes nothing here: Article L. 1222-9 of the Labour Code defines the arrangement as “toute forme d’organisation du travail dans laquelle un travail qui aurait également pu être exécuté dans les locaux de l’employeur est effectué par un salarié hors de ces locaux de façon volontaire en utilisant les technologies de l’information et de la communication”, shown on Article L. 1222-9 of the Labour Code. Télétravail, remote work, remains employment, with an employer, a payslip and contributions.
French law then tells that foreign employer exactly where to go. Article L. 243-1-2 of the Social Security Code provides: “L’employeur dont l’entreprise ne comporte pas d’établissement en France ou, s’il est un particulier, qui n’est pas considéré comme domicilié en France pour l’établissement de l’impôt sur le revenu et souhaite bénéficier de cette faculté, remplit ses obligations relatives aux déclarations et versements des contributions et cotisations sociales d’origine légale ou conventionnelle auxquelles il est tenu au titre de l’emploi de personnel salarié auprès d’un organisme de recouvrement unique, désigné par arrêté du ministre chargé de la sécurité sociale.” The official text is on Article L. 243-1-2 of the Social Security Code, and its implementing rule designates that single collection body for “Lorsque l’entreprise de l’employeur ne comporte pas d’établissement en France”, when the employer’s business has no premises in France, as shown on Article R. 243-8-1 of the Social Security Code. In practice this is the URSSAF foreign-firms service. URSSAF itself puts it in the plainest terms on its foreign firms page: a business with no premises in France that hires an employee covered by the French social security scheme must declare and pay social contributions in France. The same page confirms it covers employees working permanently on French territory who belong to the French scheme. The only standard escape is a genuine posting, called détachement, where the employee is sent temporarily and stays covered at home under a certificate known as the A1: French affiliation applies precisely where the employee does not benefit from the posting procedure. A permanent remote job is the opposite of a temporary posting, so the A1 route will not save a settled hire.
The courts enforce this territorial logic strictly, in both directions. In a ruling of 13 October 2022 on appeal number 21-13.252, the Second Civil Chamber of the Court of Cassation recalled: “s’ils ne sont pas ou ne sont plus soumis à la législation française de sécurité sociale en vertu de conventions ou de règlements internationaux, les travailleurs détachés temporairement à l’étranger par leur employeur pour y exercer une activité salariée ou assimilée, rémunérée par cet employeur, sont soumis à la législation française de sécurité sociale à la condition que l’employeur s’engage à s’acquitter de l’intégralité des cotisations dues auprès de la caisse d’affiliation du salarié.” Read the full decision on Cassation, Second Civil Chamber, 13 October 2022, appeal 21-13.252. Mirror the reasoning: coverage follows documented affiliation and international instruments, not payroll convenience. Going the other way, on 16 October 2025 the same chamber upheld a reassessment against a company seated abroad whose staff worked on French soil, holding that “à défaut de production de documents justifiant du rattachement des salariés de la société travaillant sur le sol français à la législation de leur pays d’origine, le redressement était justifié”, shown on Cassation, Second Civil Chamber, 16 October 2025, appeal 23-14.039. No proof of home-country cover for work done in France means the French bill stands. For a British remote worker this means the employer should register with the foreign-firms service, run a French-compliant payslip with French rates, and pay both shares in France, while the employee checks that National Insurance is no longer being deducted on the same salary. Paying in both countries at once is the most expensive possible outcome and the most common.
Two side issues deserve one paragraph each because clients always ask. Residence papers come first chronologically: since Brexit, a British citizen needs a right to stay and, as a rule, a right to work. Article L. 411-1 of the Code on the Entry and Stay of Foreigners states that “tout étranger âgé de plus de dix-huit ans qui souhaite séjourner en France pour une durée supérieure à trois mois doit être titulaire de l’un des documents de séjour suivants : 1° Un visa de long séjour”, meaning any foreigner over eighteen wishing to stay in France longer than three months must hold one of the listed stay documents, beginning with a long-stay visa, as shown on Article L. 411-1 of the foreigners code. A visa de long séjour, long-stay visa, and the resulting carte de séjour, residence permit, must match the reality of salaried work in France, so the visa strategy should be settled before the payroll is moved. Beneficiaries of the Withdrawal Agreement with protected status follow their own track and should not apply as newcomers. Health cover follows automatically once affiliation is correct: contributions paid in France open rights with the local health fund for the worker and, in most cases, for a family living with them, which is precisely why an employer that keeps paying only in Britain leaves its employee without a complete French health record.
B. URSSAF or the tax office has sent a demand — how do I challenge it, and what evidence actually wins?
Take every demand seriously and answer inside the deadline, because silence turns a contestable file into an enforceable debt. An URSSAF audit, called a contrôle, follows a fixed adversarial sequence: advance notice, on-site or on-documents checks, a findings letter called a lettre d’observations to which you reply, then a formal demand called a mise en demeure. The notice period is a legal guarantee, not a courtesy: Article R. 243-59 of the Social Security Code requires that “Tout contrôle effectué en application de l’article L. 243-7 est précédé, au moins trente jours avant la date de la première visite de l’agent chargé du contrôle, de l’envoi par l’organisme effectuant le contrôle des cotisations et contributions de sécurité sociale d’un avis de contrôle”, verifiable on Article R. 243-59 of the Social Security Code. If no proper notice was sent, say so first and prove it from the envelopes and the audit file. Answer the findings letter point by point, in French, attaching each exhibit it lacks, and send everything by a traceable route. The formal demand that follows can then be contested before the employer’s dedicated appeals board and, if needed, before the social chamber of the judicial court, the pôle social, within its short time limit stated on the notice itself. Miss that limit and even the best file becomes inadmissible.
Tax demands follow a parallel track: first a written claim to the tax office, called a réclamation, setting out the facts, the treaty articles and the computation, then, if the administration maintains its position, an appeal to the administrative court. Frame the claim around the three questions the inspector must answer: were you French resident that year under Article 4 B read with Article 4 of the treaty, were the disputed pounds earned by work performed in France under Article 15, and was the British tax on that same income properly credited? A claim that merely says tax was already paid in Britain, without a day-count, without the P60 and without the treaty computation is routinely rejected. Add the employment contract with the place-of-work clause, the employer’s attestation of remote working, the day-count diary with travel proof, the British tax return and tax-paid certificates, and the French returns as filed. Where both countries claim the same income, the treaty’s mutual agreement procedure, listed as Article 26 of the convention, lets the two tax authorities negotiate the case, which is worth requesting in high-value files alongside the domestic claim rather than after it has failed.
The files that win share the same evidentiary spine. Proof of where the work was really done beats every assertion: contract clause, employer’s remote-work policy, VPN and badge logs if available, travel records, and school and housing papers anchoring family life. Proof of social-security cover beats every assumption: either the British posting certificate and its exact dates, or the French registration number, the French payslips and the contribution receipts. Under the 16 October 2025 ruling quoted above, producing nothing on affiliation means the reassessment is justified, so the employer’s registration file is exhibit number one. Where contributions were paid twice — in Britain and in France on the same salary — attack both ends at once: seek correction of the undue payment on one side and credit or refund on the other, and calendar the French refund rule in Article L. 243-6, which provides that “La demande de remboursement des cotisations de sécurité sociale et d’allocations familiales indûment versées se prescrit par trois ans à compter de la date à laquelle lesdites cotisations ont été acquittées”, shown on Article L. 243-6 of the Social Security Code. Three years from payment runs faster than clients expect, so diary it the day the double payment is discovered.
Finally, fix the structure for the future while the dispute runs. An employer that wants to keep its British employee in France has three compliant paths: register directly with the URSSAF foreign-firms service and run French payroll, use a compliant employment vehicle after checking who really bears employer liability, or convert the relationship only if the reality genuinely changes, which a label alone never achieves. What never works is the letterbox fix: a British contract stating place of work London while the employee sits in France all year, a few days of hotel in London manufactured to claim the 183-day exception, or backdating a posting certificate to cover a permanent arrangement. Inspectors have seen all three, the Court of Cassation has upheld reassessments built on far less, and penalties for undeclared work sit on top of the contributions themselves. Declare the reality, pay in the right country, and keep the paper that proves it.
Conclusion
Living in France while working remotely for a British employer is perfectly lawful, but it is a two-country compliance exercise, not an extension of British payroll with a French view. French tax residence usually follows the settled home under Article 4 B and the treaty’s centre-of-vital-interests test, Article 15 of the treaty gives France the right to tax the French-worked days, and French social security claims the same salary under the place-of-work rule with registration through the foreign-firms service. Each of those three conclusions can be challenged — residence with the tie-breaker and the day-count, the salary split with travel proof, the contributions bill with posting certificates or registration papers and the three-year refund rule — but only inside the deadlines and only with documents. Put the contract, the diary, the P60 and the affiliation papers in order now, and a demand letter becomes a negotiation rather than a disaster.
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