You bought a stone house in the Dordogne before Brexit, or a two-bedroom flat in Paris as a base for work trips, and now life has moved on. Perhaps you are retiring back to Kent, divorcing, or simply releasing capital. The estate agent talks price, the buyer talks dates, and then the notaire (the French public officer who alone can complete a property sale) mentions the plus-value immobilière (the French tax on the capital gain made on a property sale) and a five-figure sum to be withheld on the day. For a British seller after Brexit this moment is full of traps: the wrong statement about where you live, a missed exemption for a former main home, or a misunderstanding of what the France-United Kingdom double tax treaty actually protects can cost tens of thousands of euros. Every French term is explained the first time it appears.

The short answer is that France taxes the gain first, because the property stands on French soil, and the treaty gives France that right expressly. Whether you still live in France or have already returned to Britain changes the legal route but rarely the starting rate: income tax at 19 per cent after the holding-period allowances, social levies on top, and a surcharge on large gains. Three genuine exits exist for British sellers — the main-home exemption, the former-main-home exemption claimed within its strict time limit, and the reinvestment exemption on a first sale — plus the British-side foreign tax credit that prevents true double taxation. Where the bill is wrong, French law gives you a formal claim (réclamation, the written complaint to the tax office) and then the administrative court (tribunal administratif, the first-level court for tax disputes). This guide works through each stage with the exact statutory wording, decided cases you can check, Paris practice, and the file to hand your notaire so the completion-day figure is right.

I. Will France tax the sale of your French house after Brexit?

A. Tax resident in France or not: why your status on the day of the sale decides everything

Start with residence, because every later computation hangs on it. French domestic law distinguishes the seller who is fiscally domiciled in France (domicilié fiscalement en France, meaning your tax home is in France) from the seller who is not. If you live in France at the date of the sale, your gain falls under the ordinary resident regime: the notaire computes the gain, applies the allowances for length of ownership, withholds the tax on completion, and files the capital-gains return. If you have already left — back to London, Edinburgh or elsewhere — you are a non-resident seller, and a special provision applies. Article 244 bis A of the Code général des impôts (the French tax code) states the principle word for word: non-resident gains on French buildings “sont soumises à un prélèvement selon les taux fixés au III bis” (are subject to a levy at the rates set in section III bis). The official tax administration page for non-residents confirms the practical result in plain language, namely a 19 per cent levy whatever the country of residence plus social levies at a combined 17.2 per cent In other words, the headline income-tax rate is the same 19 per cent whether you live in Croydon or Cahors, and the social levies apply at a combined 17.2 per cent, subject to the British-specific relief explained below.

Brexit changed the legal reasoning without changing that headline. Before 2021 the United Kingdom sat inside the European Union, so British sellers automatically shared the European-resident rate path. Since 1 January 2021 the United Kingdom is a third country, and the question became whether Britons would suffer the higher third-country levy that once reached one third of the gain. The administration’s answer, published on the official non-resident capital-gains page of impots.gouv.fr, is reassuring on the rate: the 19 per cent levy applies whatever the country of residence. The two leading decisions of the Conseil d’État (the Council of State, France’s highest administrative court) explain why courts policed exactly this rate gap for years. In Conseil d’État, 9th chamber, 23 June 2022, No 445785, a Swiss seller domiciled in Monaco challenged the old one-third levy on a 2012 Nice sale; the file records that “la cession par M. B…, ressortissant suisse résidant à Monaco, le 20 mars 2012, d’un ensemble immobilier situé à Nice lui a permis de réaliser une plus-value immobilière assujettie au prélèvement prévu par l’article 244 bis A” and that he obtained in the proceedings a “dégrèvement d’un montant égal à la fraction de cet impôt excédant le taux de 19 % applicable aux plus-values immobilières réalisées par les résidents de France, de l’Union européenne et des autres Etats parties à l’accord sur l’Espace économique européen (EEE)”. The companion ruling, Conseil d’État, 9th-10th chambers combined, 12 February 2020, No 415475, states the general rule word for word: “les personnes physiques qui ne sont pas fiscalement domiciliées en France au sens de l’article 4 B du même code, sont soumises, sous réserve des conventions internationales, à un prélèvement spécifique sur les plus-values résultant, notamment, de la cession de biens immobiliers”. For a British seller today the lesson is simple: expect the 19 per cent route, keep the decision numbers above for any argument with the tax office, and never accept a higher rate without a written legal basis.

Residence also decides which exemptions you may even invoke, and here the statute is deliberately narrower for non-residents. The same 2020 Council of State ruling, Conseil d’État, 9th-10th chambers combined, 12 February 2020, No 415475, holds that “Le renvoi, par le 1° du paragraphe II de l’article 244 bis A du même code, aux seuls 2° à 9° du paragraphe II de cet article 150 U a pour effet d’exclure les personnes physiques non fiscalement domiciliées en France lors de la cession de leur bien immobilier du bénéfice de l’exonération prévue en faveur de la première cession d’un logement autre que la résidence principale.” Concretely, this asymmetry closes several resident-only reliefs to sellers who are non-resident on the day of completion. Concretely, several resident-only reliefs — including the first-sale reinvestment relief discussed in Part II — are closed to you once you are non-resident on the day of completion, while one dedicated non-resident relief for a former main home remains open under Article 244 bis A itself. Date your departure carefully, therefore: the notaire will ask for your address, your tax notices, and sometimes your British tax-residence confirmation, and the answer given in the deed (acte de vente, the formal sale deed) determines the whole downstream treatment. A seller who moved back to Manchester in March but completes in June is a non-resident seller, with the non-resident set of reliefs and none of the resident-only ones.

The treaty does not remove France’s right to tax; it organises it. Article 14 of the France-United Kingdom double tax convention of 19 June 2008, in force, as published by the British government gives France the right to tax gains on French immovable property Your Dordogne cottage or Paris flat is immovable property situated in France, so France may tax the gain, and the United Kingdom, where you may also be taxable as a British resident on worldwide gains, eliminates the resulting double taxation by credit. Our companion analysis of the France-United Kingdom treaty for British residents in France explains that credit mechanism in detail; for sellers the point to retain is that paying in France is normal, paying twice on the same gain is not, and the British self-assessment return must claim the foreign tax credit with the French completion statement attached.

B. The rate stack on a French sale: 19 per cent tax, social levies, the holding-period allowances and the high-gain surcharge

With the principle settled, turn to the arithmetic, because the completion-day figure is a stack of four layers and each has its own statute. Layer one is income tax at 19 per cent on the net taxable gain. The English-language page of the French public service, service-public.fr page F10864 on real-estate capital gains, states a 19 per cent rate on the gain after allowances, with a worked illustration of €3,800 of tax on a €20,000 taxable gain That illustration is worth keeping for a sense of scale: a €100,000 taxable gain means €19,000 of income tax before any other layer, and a €300,000 taxable gain means €57,000.

Layer two is time, and time is the seller’s best friend. Article 150 VC of the tax code sets the allowance for length of ownership (abattement pour durée de détention, the statutory reduction of the taxable gain for each year you have owned the property) word for word: “6 % pour chaque année de détention au-delà de la cinquième” (6 per cent for each year of ownership beyond the fifth) and “4 % au titre de la vingt-deuxième année de détention” (4 per cent for the twenty-second year). The combined effect, confirmed by the same public-service page, is full income-tax exemption after twenty-two years of ownership Social levies follow a slower clock, with full exemption from social levies only after thirty years A concrete timeline helps. Buy in 2010 and sell in 2026 after sixteen years: eleven allowance years at 6 per cent cut 66 per cent of the gross gain for income tax, while the social-levy allowance, which runs on its own scale, cuts less, so a substantial social charge remains. Buy in 2000 and sell in 2026 after twenty-six years: income tax is gone entirely, but social levies still bite on the fraction above their own allowance until the thirtieth anniversary. Ask your notaire for the two-column simulation — income tax column, social-levies column — before signing the preliminary contract (compromis de vente, the binding pre-contract), because the net proceeds differ enormously between year twenty-one, year twenty-three and year thirty-one.

Layer three is the social levies themselves (prélèvements sociaux, the French social charges added to the income tax on capital gains), and this is where British sellers have a genuine post-Brexit advantage to protect. The starting rule for non-residents is the combined 17.2 per cent quoted above. But the same official page continues with a British-specific paragraph: persons covered by a compulsory social-security scheme of an EEA country or Switzerland have been exempt from the CSG and CRDS on such gains since the 2018/2019 reforms, British residents keep that exemption despite Brexit, and the gains remain subject only to the 7.5 per cent solidarity levy In practice a British seller affiliated to the British system — typically holding a British-issued S1 healthcare form or otherwise covered by the United Kingdom system rather than the French one — pays the 7.5 per cent solidarity levy instead of the full CSG/CRDS-inclusive charge. The administrative courts have enforced exactly this single-legislation logic for years: in Administrative Court of Appeal of Marseille, 4th chamber, 17 March 2020, No 19MA00148, the claimant argued that “dès lors qu’il est affilié à un régime de sécurité sociale étranger et non pas français, les dispositions du règlement n° 883/2004 font obstacle à ce qu’il soit assujetti aux prélèvements sociaux”, the European coordination regulation on social security. Keep your affiliation proof — S1, British national-insurance record, certificate of coverage — in the sale file, because the exemption is not automatic: it must be claimed with evidence.

Layer four is the surcharge on large gains (surtaxe sur les plus-values élevées, the extra tax on taxable gains above €50,000), and it surprises sellers who thought 19 per cent was the ceiling. Article 1609 nonies G of the tax code imposes a progressive surcharge from 2 per cent to 6 per cent on the taxable gain above €50,000, with smoothing bands — the published scale runs from the “De 50 001 à 60 000” band at “2 %” up through “100 001 à 110 000” at “3 %”, “150 001 à 160 000” at “4 %”, and “Supérieur à 260 000” at “6 %”. Take a €120,000 taxable gain: income tax at 19 per cent is €22,800, social levies add roughly €20,600 at the full rate or far less with the British relief, and the surcharge adds around €3,600. Take a €300,000 taxable gain: income tax €57,000, social levies substantial, surcharge at 6 per cent €18,000. The surcharge applies per sale and, for a jointly owned property, per share of gain — a point to verify with the notaire where spouses own unequal shares. Add the pieces together and a large short-held gain can easily face an all-in French burden above 35 per cent of the taxable gain, while a long-held modest gain can fall to a few per cent or zero. That spread is exactly why the exemptions in Part II matter more than any haggling over the price.

II. How do you lawfully cut the bill and challenge it when it is wrong?

A. The exemptions a British seller can actually use: main home, former main home, first-sale reinvestment and the treaty credit

The main-home exemption (exonération de la résidence principale, the full exemption for the sale of the home where you actually live) is the most valuable and the most audited. Article 150 U of the tax code opens the exemption list with the sentence every seller should know by heart: “Qui constituent la résidence principale du cédant au jour de la cession” (dwellings which are the seller’s main home on the day of completion). Three words do the work: main, home, on the day. The exemption is total — no income tax, no social levies, no surcharge — but only if the property sold is genuinely your main home when the deed is signed. The courts apply a factual test of effective, habitual occupation, weighing the bundle of evidence: where you sleep, where your children go to school, where your electricity and broadband consumption sits, which address appears on your income-tax return, your taxe d’habitation (the French residence tax) and your taxe foncière (the French property-ownership tax) notices. In Administrative Court of Appeal of Douai, 2nd chamber, 6 February 2018, No 16DA01692, the administration “a remis en cause le régime d’exonération des plus-values prévue par les dispositions du II de l’article 150 U du code général des impôts au motif que cet immeuble ne constituait pas la résidence principale de M. A…et de Mme C…à la date de la vente”, and the court examined the occupation evidence in detail. The warning for British owners is blunt: a Dordogne cottage lived in for three summer weeks a year, with council tax paid in Bristol and French utility bills near zero, is not a main home, and claiming it as one invites reassessment with interest and penalties.

The civil courts add a professional sting to the same point. In Court of Cassation, First Civil Chamber, 22 September 2021, No 19-23.506, a seller’s deed stated in its tax declarations paragraph that the property sold was her main home and the transfer therefore exempt; the file summary records that “par acte authentique reçu le 12 août 2011 par M. [D], avec la participation de M. [E] (les notaires), Mme [V] a vendu à la société civile immobilière ALT 2 deux lots d’un ensemble immobilier”, yet “L’acte mentionnait au paragraphe « déclarations fiscales » que le bien vendu constituait la résidence principale de Mme [V] et qu’en conséquence la mutation était exonérée d’impôt sur la plus-value”. The seller then sued the two notaires who had drawn up the deed, and the Court of Cassation ruled “Vu l’article 1382, devenu 1240 du code civil”, the general fault-and-damage provision of the Code civil (the French civil code), sending the lower court back to examine the notaires’ own knowledge and advice. Two lessons follow for British sellers. First, never press a notaire to write “résidence principale” into the deed unless it is true on the day; the reassessment lands on you, not on the officer. Second, expect a careful notaire to ask for proof — tax returns, school certificates, utility records — and to refuse the exemption wording where the proof does not support it; that refusal protects you.

Three further reliefs deserve a checklist, because each fits a different British life story. First, the former-main-home relief for sellers who have left France. The official non-resident page states that a dedicated relief exempts a non-resident seller on the former French main home kept since departure abroad, subject to strict conditions the page details: the seller must have kept exclusive personal use of the former main home between departure and sale, and time limits apply to the sale after departure. The same page adds a trap worth reading twice: a non-resident seller who takes this 244 bis A relief cannot then also claim the separate resident reinvestment relief of Article 150 U II 2°, and where the relief applies the non-resident seller files no capital-gains return, with the deed recording the legal basis of the exemption. If you left Lyon for Leeds eighteen months ago and your old flat has stood empty awaiting sale, this is your provision — but instruct your notaire early, because the exclusive-use condition fails the moment the flat is let, even briefly.

Second, the first-sale reinvestment relief (exonération de la première cession sous condition de remploi, the exemption on the first sale of a dwelling other than the main home where the price is reinvested in a main home), strictly for sellers still resident in France. The statute grants it for the first sale of a dwelling other than the main home where the seller has not owned a main home in the four years before the sale and reinvests the price in a main home within two years. The public-service English page summarises the two conditions as reinvesting the price in a main home within two years and not having owned a main home in the four years before the sale. Picture a British teacher renting in Paris for a decade while letting out a studio in Lille: selling the studio and using the proceeds within two years to buy the Paris main home can exempt the Lille gain. The relief is all-or-nothing on reinvestment — partial reinvestment gives partial exemption only under the statute’s own formula — and, as the Council of State ruling above confirms, it is unavailable once you are non-resident. Third, the British-side credit: where France has taxed the gain under Article 14 of the treaty, the United Kingdom taxes the same gain under its own capital-gains rules and gives credit for the French tax within the treaty limits. Keep the French completion statement (décompte du notaire, the notaire’s statement of tax paid), the capital-gains return reference, and proof of payment: HM Revenue and Customs will ask for all three, and the credit cannot exceed the British tax on the same gain.

A housekeeping point closes the list: works, purchase costs and sale costs adjust the taxable base before any rate applies. The acquisition price may be increased by documented purchase costs — registration duty or the flat-rate allowance in lieu, notaire fees, agency commission on purchase — and by genuine improvement works (travaux d’amélioration, building works that improve the property, as opposed to mere repairs) proved by invoices from registered firms, held for the statutory period. The sale price may be reduced by sale costs such as agency commission on sale and mandatory survey costs (diagnostics, the compulsory technical surveys annexed to the deed). A British seller who kept every invoice since 2008 routinely cuts the taxable gain by 10 to 20 per cent against a seller with no paper. Start the folder now: completion statements, invoices with the property address, planning permissions, and the procès-verbal of any extension. Estimates, cash payments without invoices, and works by unregistered hands count for nothing.

B. Challenging the assessment: the notaire file, the formal claim and the court route with Paris practice

Most disputes are won or lost before completion, in the notaire’s office, because the tax is computed, declared and paid at the signing table. The declaration of the gain, the computation of allowances, the surcharge band, the social-levy relief for British-affiliated sellers, and any accredited-representative formalities for non-resident sellers from outside the European Economic Area all pass through that single file. Arrive with the complete pack and the figure is usually right first time; arrive light and you will be paying first and arguing later. The pack for a British seller is: passports and birth certificates with sworn translations where names differ; marriage or civil-partnership regime evidence, because the default matrimonial property regime decides who is taxed on which share; the full chain of title with the acquisition deed and price; every works invoice with proof of payment; the last three French income-tax notices (avis d’imposition, the annual tax assessment) and the property-tax notices; British tax-residence confirmation and, for the social-levy relief, the S1 form or affiliation certificate; the energy-performance and survey file; and, for an exemption claim, the residence proof bundle — electoral registration, school enrolment, utility consumption records, and the address history. Where the sellers are divorcing, add the divorce petition or decree: the attribution of the gain between spouses follows the matrimonial regime and the court orders, and the Paris notaires will not split a gain fifty-fifty on a bare assertion.

Paris practice adds three points worth knowing before you instruct. First, completion diaries in Paris run on the notaire’s banking timetable: funds for the tax levy are called days before signing, and a file whose British bank transfer lands late postpones completion with penalty interest to the buyer. Second, Paris leaseback and tenant-occupied sales raise the residence question automatically: a flat sold with a sitting tenant (occupé, sold let) cannot simultaneously be your main home on the day, so the exemption paragraph will be refused and the full computation applied. Third, high-value Paris sales routinely trigger the surcharge bands above, and the Chambre des notaires de Paris (the Paris chamber of notaries) expects the simulation to show each band separately; ask for that breakdown in writing, because it is also the document your British accountant needs for the foreign tax credit. None of this is hostility to British sellers — it is the standard protective routine of an officer who answers personally for the tax figure in the deed.

Where the figure is wrong despite the file, French procedure gives you a two-stage remedy, and the first stage is compulsory. Article L190 of the Livre des procédures fiscales (the tax procedure code) opens the contentious jurisdiction word for word: “Les réclamations relatives aux impôts, contributions, droits, taxes, redevances, soultes et pénalités de toute nature, établis ou recouvrés par les agents de l’administration, relèvent de la juridiction contentieuse lorsqu’elles tendent à obtenir soit la réparation d’erreurs commises dans l’assiette ou le calcul des impositions, soit le bénéfice d’un droit résultant d’une disposition législative ou réglementaire.” The written claim (réclamation contentieuse) goes to the tax office that collected or assessed the levy, normally the non-resident tax office (Service des impôts des particuliers non-résidents, the tax office for non-residents at Noisy-le-Grand) for sellers back in Britain, or the local office of the property for sellers still in France. Time limits are strict and short: the claim must generally reach the office by 31 December of the second year after the levy was paid or the assessment notified, with longer periods only in narrow statutory cases. Send it by registered letter with acknowledgment (lettre recommandée avec accusé de réception) or through the secure messaging of your French tax account, state the legal basis article by article, attach the deed extract, the computation, the payment proof and the exemption evidence, and ask expressly for discharge (décharge, the cancellation of the tax) or reduction (réduction) plus default interest (intérêts moratoires, the statutory late-payment interest the state owes on sums it must repay). An unanswered claim after six months is an implied refusal you may take to court; an express refusal restarts the clock for the court application.

The court stage belongs to the administrative courts: the tribunal administratif of the property’s location at first instance, the administrative court of appeal (cour administrative d’appel, the appeal court for tax cases) above it, and the Conseil d’État on points of law. Your petition must repeat the claim’s legal bases, add the refusal decision, and quantify the discharge sought euro by euro — income tax, each social levy, surcharge, interest and penalties separately, because judges grant and refuse line by line. The four decisions quoted in this guide show how judges reason: rate parity for non-residents in No 445785, the closed list of non-resident exemptions in No 415475, the factual residence test in the Douai ruling, and the single social-security legislation argument in the Marseille ruling. Cite them by number and date, annex the official printouts from legifrance.gouv.fr, and explain in one paragraph each why your facts match. Where the dispute turns on European Union law — for example the social-levy affiliation question for a seller covered by the withdrawal agreement’s social-security protocol — plead the European provision expressly and ask the court, if needed, to seek interpretation; administrative judges apply European law of their own motion in tax matters, but a clearly pleaded European ground is decided faster. Costs are moderate — no court fee for the claim itself, counsel fees as agreed — and the state pays default interest on sums repaid, which on a large gain over several years is itself significant.

Two final cautions keep the challenge credible. First, do not stop paying or instruct the notaire to withhold nothing on the strength of your own legal theory: the levy is collected at completion, and contesting afterwards through the claim-and-court route recovers money with interest, while blocking completion exposes you to buyer litigation for late delivery. Second, do not run the British and French tracks in the wrong order: complete the French claim first and obtain the revised French assessment before filing the amended British return, because the British credit follows the final French tax, not the provisional figure. Sellers who reverse the order spend a year reconciling two moving assessments. The disciplined sequence is: complete with the best file, claim in writing within the deadline, litigate the refusal where the euros justify it, and only then close the British return with the final French documents. That sequence is also the one a Paris tax lawyer can execute without reinventing your file.

Conclusion

Return to the Dordogne house or the Paris flat and the completion-day figure that started this guide. The British seller who does well works three questions in order. First, where am I domiciled for tax on the day of the deed, and which set of reliefs — resident or non-resident — does that open. Second, what does the arithmetic stack look like on my exact holding period: 19 per cent income tax after the twenty-two-year allowance curve, social levies at 17.2 per cent softened to the 7.5 per cent solidarity levy where British affiliation is proved, and the 2 to 6 per cent surcharge above €50,000. Third, which exemption genuinely fits my story — true main home on the day, former main home sold within its conditions after departure, first-sale reinvestment while still resident — and what paper proves it. The sellers who lose money skip one of the three: they claim a main home they left years ago, they let the former home and destroy the exclusive-use condition, or they complete with no works invoices and pay tax on a gain they never truly made. The sellers who keep their money do the opposite: they date their residence honestly, they hand the notaire a complete, translated, receipted file, they claim the British social-levy relief with affiliation proof, and where the assessment is wrong they file the formal claim within its deadline citing the statute and the four decisions by number. France taxes the French sale first and the treaty says it may; the rest — allowances, exemptions, credit, claim, court — is procedure, and procedure rewards the prepared.

Need a quick opinion on your case.

If you are selling a French house or flat as a British owner, or if the completion statement or a later assessment looks wrong, our firm advises British sellers in English on valuations, allowances, exemptions, social-levy relief and formal claims, including before the Paris administrative court. Telephone consultation: 80 EUR including tax, within 48 hours with a lawyer of the firm. Call 06 46 60 58 22 or write via our contact page. We receive clients in Paris and across Île-de-France.