You bought a stone farmhouse in the Dordogne, or a flat near the coast, back when a British buyer was still a European buyer. Since Brexit you live there part of the year, or you have moved back to the United Kingdom and the house has become a holiday home that costs more than it gives. Now an estate agent tells you the market is right, and a buyer is ready. Before you sign anything, one question matters more than the sale price: how much French tax will be taken from the gain, will Britain tax you a second time, and what can you do if the bill looks wrong? This guide answers those three questions in order. It explains how France calculates the capital gain on a second home sold by a British owner, which allowances reduce it, why the notaire (the French public officer who handles conveyancing and collects the tax) asks for a stack of invoices before the signing, how the France-United Kingdom double tax treaty allocates the right to tax between Paris and London, and how to challenge an excessive assessment. Every French term is explained at first use, and every decisive rule is quoted from the official text so you can check it yourself.

I. How France calculates your capital gains bill and what the notaire will ask you to prove

A. What will I actually pay if I sell my French second home as a British seller?

France taxes the sale first, because the property is on French soil. The relevant charge, set by the French General Tax Code, is the plus-value immobilière, the tax on real-estate capital gains realised by private individuals on sales for consideration of built or unbuilt property. Your second home is fully within this charge: the only dwellings that escape it are your main home and a narrow list of special cases. A holiday house in France owned by a British resident of the United Kingdom, or by a British resident of France who lives in it only a few months a year, is not a main home, so the gain is taxable.

The calculation starts with a simple subtraction, then applies a series of reliefs. The gross gain is the sale price minus the purchase price, with both sides adjusted. On the purchase side you may add the acquisition costs, meaning the stamp duty and notaire’s fees you paid when you bought: service-public.fr states that you can count acquisition fees, meaning registration fees and notaire fees, either at their evidenced amount or as a flat 7.5% of the purchase price (official calculation guide). In practice the 7.5% flat rate often beats the real costs for older purchases, because duty rates were lower and receipts get lost. On top of that you may add the cost of building works carried out by a registered firm, evidenced by invoices, and the cost of certain fittings. On the sale side you deduct the estate agent’s commission you paid and the cost of mandatory surveys. The result is the gross plus-value.

That gross gain is then reduced by a holding-period allowance, called an abattement pour durée de détention, which works on two different clocks. For income tax, article 150 VC fixes the allowance at “6 % pour chaque année de détention au-delà de la cinquième” and “4 % au titre de la vingt-deuxième année de détention”, after which the gain is entirely exempt from income tax. For social levies, the prélèvements sociaux (the French social charges levied on capital income alongside income tax), the allowance runs far more slowly: 1.65% per year from the sixth to the twenty-first year, 1.6% for the twenty-second year, then 9% per year, with full exemption only after thirty years. Service-public.fr gives the example of a property held for ten years with a gain of 10,000 euros: the income-tax allowance is 30% (6% for each of the five years from year six to year ten), so income tax is charged on 7,000 euros only, while the social-levies allowance is 8.25% (1.65% for each of those five years), so the levies bite on 9,175 euros. The two clocks explain why a sale after, say, twenty-five years can be free of income tax yet still carry a visible social-levies charge: the worked example on the same official page shows a 55% total reduction for social levies after twenty-five years, leaving 4,500 euros of a 10,000-euro gain still taxable to the levies.

Once the allowances are deducted, the remaining taxable gain is charged at a flat rate of 19% for income tax. The official English-language page applies a flat 19% income-tax rate to the gain after allowances (official calculation guide). Social levies apply on top, at the overall statutory rate in force on the date of sale, so you must check the current rate on the official page before signing rather than relying on old forum posts. Very large gains attract a further surtax, the surtaxe sur les plus-values élevées: an additional surtax on large gains whose rate rises from 2% à 6% with the amount of the gain. The whole computation is set out on form 2048-IMM-SD, the capital-gains return for property sales, and in practice you never fill it in yourself: the return contains a computation table that the notaire completes (official calculation guide). For vendors living outside France, the same 19% is charged as a withholding tax: article 244 bis A provides that “les personnes physiques, les associés personnes physiques de sociétés, groupements ou organismes dont les bénéfices sont imposés au nom des associés et les porteurs de parts, personnes physiques, de fonds de placement immobilier mentionnés à l’article 239 nonies sont soumis au prélèvement au taux de 19 %”. The same article fixes payment mechanics: “L’impôt dû en application du présent article est acquitté lors de l’enregistrement de l’acte ou, à défaut d’enregistrement, dans le mois suivant la cession, sous la responsabilité d’un représentant établi en France, accrédité par l’administration fiscale.” The notaire withholds the tax from the sale proceeds on the day of the acte de vente, the formal deed of sale, and pays it to the Treasury. That is why the notaire, not you, has the last word on the figures, and why checking the notaire’s draft computation before the signing appointment is the single most valuable step in the whole process.

Two Brexit-specific traps sit inside this machinery. First, the general code provisions on property gains, articles 150 A bis to 150 VH of the French General Tax Code, contain a capped exemption for sellers who have left France: article 150 U exempts, up to 150,000 euros of net taxable gain, a seller who is a non-resident individual formerly tax-resident in France. But the text limits this to a seller who is “lorsque le cédant est une personne physique, non résidente de France, ressortissante d’un Etat membre de l’Union européenne ou d’un autre Etat partie à l’accord sur l’Espace économique européen ayant conclu avec la France une convention d’assistance administrative en vue de lutter contre la fraude et l’évasion fiscales et à la condition qu’il ait été fiscalement domicilié en France de manière continue pendant au moins deux ans à un moment quelconque antérieurement à la cession”. Since Brexit, a British-only national is no longer a national of a European Union member state or of the European Economic Area, so this 150,000-euro shelter is closed to British sellers unless they also hold European Union nationality. Many British owners who left France around or after Brexit assume the exemption still covers them; it does not.

Second, a British seller who still lives in the United Kingdom is treated as a non-resident vendor, and non-resident vendors face an extra formality. If you live in Britain and sell for more than 150,000 euros, you must appoint a représentant fiscal, an accredited tax representative established in France who guarantees payment of the tax, before the deed is published (official non-resident seller guide). The guide imposes this duty on vendors not living in a European Economic Area state (apart from Liechtenstein) above that sale-price threshold. The representative can be a permanently accredited company, a French bank, the buyer if the buyer is French tax-resident, or any other French tax-resident person, but one person is excluded: the notaire handling the sale cannot act as that representative (official non-resident seller guide). Appointing the representative takes weeks, because the accreditation must be granted by the property-tax office of the place where the house sits before publication of the deed. A sale agreed in principle in June can easily slip to autumn if this step is discovered late, and British vendors are the first victims because the obligation only bites outside the European Economic Area.

B. How long must I have owned the property to cut the bill, and which papers reduce it?

The holding period is the most powerful lever you control, and it rewards patience on two different timetables. For income tax, the finishing line is twenty-two years: at 6% a year from year six to year twenty-one (sixteen years, giving 96%) plus 4% in year twenty-two, the allowance reaches 100% and the gain escapes income tax altogether. For social levies the finishing line is thirty years: 1.65% a year over the same sixteen years (26.4%), plus 1.6% in year twenty-two, plus 9% a year from year twenty-three to year thirty (eight years, giving 72%), which together extinguish the levies base. A property bought in 2004 and sold in 2026, after twenty-two years, therefore pays no income tax on the gain but still pays social levies on roughly a sixth of it; the same property sold in 2034, after thirty years, pays neither. If your sale is not urgent, asking the notaire to model the bill at several anniversary dates is straightforward and sometimes saves thousands of euros for a few months of waiting, because each anniversary is counted in full years from the date of the purchase deed.

Short of waiting, the bill is reduced by every euro of purchase price, acquisition cost and qualifying works you can prove. British sellers lose money here more often than through any rate change, because the evidence sits in another country, in another language, or with a builder who has retired. The purchase-price rule is laid down by article 150 VB: “Le prix d’acquisition est le prix effectivement acquitté par le cédant, tel qu’il est stipulé dans l’acte”. If you inherited the house or received it as a gift, “le prix d’acquisition s’entend de la valeur retenue pour la détermination des droits de mutation à titre gratuit”, which is why an old undervaluation can strangely inflate today’s gain. The same article authorises the flat-rate uplift: acquisition costs “que le cédant peut fixer forfaitairement à 7, 5 % du prix d’acquisition dans le cas des immeubles”. Works qualify only as “Des dépenses de construction, de reconstruction, d’agrandissement ou d’amélioration, supportées par le vendeur et réalisées par une entreprise”, and where a building sold more than five years after acquisition lacks invoices, “une majoration égale à 15 % du prix d’acquisition est pratiquée”. Acquisition costs are the 7.5% flat rate or the evidenced real amount, as explained above. Works must have been carried out by a professional firm and supported by invoices showing the address of the property, the nature of the works and the amount paid; do-it-yourself materials, paid cash without invoices, do not count, and works already deducted against rental income cannot be counted a second time. One recent change deserves attention from British owners who let their second home between stays: for sales since 15 February 2025, depreciation deducted under the furnished non-professional rental regime, the location meublée non professionnelle, is added back into the taxable gain under certain conditions. If you declared furnished-rental depreciation on your French return, warn the notaire so the computation reflects it, rather than discovering the adjustment in a reassessment two years later.

Two further reliefs deserve a check before you accept that the full bill is due. The first is the main-home exemption: gains on the sale of your main home are entirely exempt, and a British owner who actually moved into the French house as the centre of family life before selling may qualify, but the tax office applies a bundle-of-evidence test (electoral roll, school enrolment, utility consumption, tax household) and reclassifies convenient relabelling without mercy. Do not claim this exemption on a house you visited for holidays; the penalty for a false claim exceeds any saving. The second is the first-sale reinvestment relief: a seller who has not owned a main home for four years and reinvests the price in a future main home within twenty-four months can shelter the gain proportionally, a route that occasionally helps a British renter in London selling a French holiday flat to fund a first main home. Both reliefs turn on dates and occupation evidence, so assemble the proof ( council-tax equivalents, taxe d’habitation records, energy bills, moving invoices) before the notaire finalises form 2048-IMM-SD, because corrections after the deed is signed require a formal claim instead of a simple draft amendment.

A final timing point concerns exceptional development-area allowances. Where the buyer undertakes to demolish and rebuild collective housing in designated high-demand zones, an exceptional allowance of up to 60%, 70% or 85% of the gain can apply depending on the programme and the share of social or intermediate housing, provided the preliminary contract was signed within the statutory window. These schemes change with each finance law and depend on the buyer’s enforceable undertaking, not on your wishes, so treat them as a question to put to the notaire (whether the buyer’s project opens an exceptional allowance and what undertaking must appear in the deed) rather than as a discount you can grant yourself.

II. How to avoid paying twice and how to challenge a bill that looks wrong

A. Will HMRC tax me again on the same sale and how does the France-UK treaty prevent double tax?

Paying French tax does not automatically settle the British side. If you are resident in the United Kingdom for tax purposes, His Majesty’s Revenue and Customs taxes your worldwide gains, including the gain on a French holiday home. The British position is stated plainly on GOV.UK’s overseas-property page: United Kingdom residents pay Capital Gains Tax when they dispose of overseas property and must declare the French sale on the foreign pages of the Self Assessment return, converting euros at a consistent exchange rate and keeping the French computation as evidence. The same page warns that tax may also be due in the country where the gain arose, and that relief may be claimed where both countries tax the same gain. That relief comes from the France-United Kingdom double tax treaty, the 2008 convention presently in force, and it works by allocation plus credit rather than by exemption.

The treaty’s capital-gains article gives France the first right to tax, because the house stands in France. capital-gains article gives France the first right to tax gains on immovable property situated in France, entitling it to France is entitled to apply its 19% plus levies under its own rules, which is exactly what the notaire collects. The same gains remain declarable in the United Kingdom if you are British-resident, but the treaty then obliges the United Kingdom to relieve the double charge by credit. double-tax relief article then obliges the United Kingdom to allow the French tax paid in accordance with the treaty on the same gains as a credit against the British tax computed on those gains. Three practical consequences follow. First, the credit only covers French tax computed on the same gain and in accordance with the treaty, so keep the 2048-IMM-SD computation and the deed: HMRC will ask for them. Second, the credit cannot exceed the British tax on that same gain, so if the French bill is heavier than the British one, the excess is not refunded by London; the treaty prevents double taxation, not the heavier of two single taxations. Third, the mechanics differ with your residence: a British-resident seller claims Foreign Tax Credit Relief on the Self Assessment return, while a seller resident in France declares the worldwide gain in France and is generally not taxable in London on the French house at all, subject to the treaty tie-breaker if both countries claim residence.

One Brexit-specific question recurs at this stage: as a British person affiliated to the British social-security system rather than the French one, can you escape French social levies on the gain? The answer, developed through a decade of litigation, is no. Under European Union coordination rules, a person is subject to the social-security legislation of one member state only, and levies that specifically finance a social-security scheme follow that allocation. The Court of Justice’s de Ruyter ruling therefore discharged European Union residents affiliated elsewhere in the Union from French social levies on capital income. The Conseil d’État, France’s supreme administrative court, spelt out the governing test in a 19 December 2018 decision: “l’élément déterminant aux fins de l’application de ces règlements réside dans le lien, direct et suffisamment pertinent, que doit présenter la disposition en cause avec les lois qui régissent les branches de sécurité sociale que ces règlements énumèrent, le critère déterminant étant celui de l’affectation spécifique d’une contribution au financement d’un régime de sécurité sociale” (Conseil d’État, 19 December 2018, No. 409153). But the same court then drew the post-Brexit-relevant line in a 5 March 2018 decision on third-country residents: the Court of Justice had held that “les articles 63 et 65 du traité sur le fonctionnement de l’Union européenne doivent être interprétés en ce sens qu’ils ne s’opposent pas à la législation d’un Etat membre, telle que la législation française, en vertu de laquelle un ressortissant de cet Etat membre, qui réside dans un Etat tiers autre qu’un Etat membre de l’Espace économique européen ou la Suisse, et qui y est affilié à un régime de sécurité sociale, est soumis, dans cet Etat membre, à des prélèvements sur les revenus du capital au titre d’une cotisation au régime de sécurité sociale instauré par celui-ci, alors qu’un ressortissant de l’Union relevant d’un régime de sécurité sociale d’un autre Etat membre en est exonéré en raison du principe de l’unicité de la législation applicable en matière de sécurité sociale” (Conseil d’État, 5 March 2018, No. 397881). The United Kingdom is now precisely such a third state, neither in the European Union nor in the European Economic Area nor Switzerland. A British seller affiliated in the United Kingdom therefore remains liable to French social levies on the French gain, while a French sale by a person affiliated in Ireland or Spain is treated differently. Do not let an adviser import a pre-Brexit European Union exemption into a British file: the Conseil d’État’s third-country reasoning forecloses it.

B. My bill looks wrong — how do I challenge the calculation, the notaire’s figures or the tax demand?

Errors cluster in five places, and each has its own remedy, so the first step is always diagnosis before procedure. The usual suspects are: a purchase price taken from the wrong deed (for example the price of a neighbouring plot bought the same year); acquisition costs or works omitted because the invoices reached the notaire after the draft was frozen; the wrong starting date for the holding period, often by counting from a preliminary contract, the compromis de vente, instead of the final deed; an allowance table applied on the income-tax clock to the social levies, or vice versa; and the representative’s fee or the surtax added twice. Ask the notaire for the full 2048-IMM-SD draft with its appendix table, check each line against your own deeds and invoices, and have any correction made before the acte de vente is signed. A pre-signature correction costs an email; a post-signature correction costs a formal tax claim.

If the deed is already signed and the tax has been withheld, the route is the standard tax-contentious claim, the réclamation contentieuse. You write to the tax office that collected the levy, setting out the error and enclosing the proof, and you ask for discharge or reduction. This is not a favour you request but a right the code defines. Watch the clock: article R*196-1 of the Tax Procedures Code requires that claims “doivent être présentées à l’administration au plus tard le 31 décembre de la deuxième année suivant celle”, and for tax withheld without any assessment notice, such as the notaire’s deduction at signing, time runs from the “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”: “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.” A wrong allowance rate is an error in the base and calculation of the assessment; a forgotten treaty credit or a wrongly refused exemption is the benefit of a right resulting from legislation. Either formulation opens the contentious jurisdiction, which means a judge can ultimately decide. File the claim as soon as the error is spotted, keep proof of sending, and continue to meet every other deadline in parallel, because the claim does not suspend collection on its own: if the Treasury issues a recovery notice while your claim is pending, you must request a stay, the sursis de paiement, expressly and, where required, offer guarantees.

If the administration rejects your claim, expressly or by silence, the next judge is the administrative tribunal, the tribunal administratif, of the place where the property sits. The time limit is short and strict: “La juridiction ne peut être saisie que par voie de recours formé contre une décision, et ce, dans les deux mois à partir de la notification ou de la publication de la décision attaquée.” Two months run from notification of an express rejection, and an implied rejection through silence can equally be referred to the tribunal, so diary the date of your claim and do not wait for a courtesy reply that may never come. Your application should attach the 2048-IMM-SD computation, both deeds, the invoices the notaire omitted or misread, the representative’s accreditation where relevant, and, for a treaty point, the British return showing the same gain with its Foreign Tax Credit Relief computation. Tribunals decide these files largely on paper, so a clear chronological bundle with numbered exhibits beats a long letter. If the dispute turns on European Union coordination or treaty interpretation rather than arithmetic, ask your lawyer whether a stay pending a pilot decision or a reference is realistic; the social-levies saga shows that courts do refer such questions, but they do so on points of principle, not to correct a misread invoice.

A distinct defendant appears where the mistake is the notaire’s rather than the Treasury’s. The notaire owes a duty of advice and verification on the tax computation: checking the holding-period start date, applying the correct allowance tables, claiming the exemptions the file supports, and warning a British vendor about the representative obligation before the timetable collapses. Where a notaire’s error causes a surcharge, interest or a lost exemption, the remedy is a civil liability action before the civil courts, seeking damages equal to the loss caused, for example the social levies paid on a base that should have been reduced, or the price reduction conceded because the representative was appointed in emergency at premium cost. Sue the Treasury for the Treasury’s errors through the tax claim; pursue the notaire for the notaire’s errors through civil liability; and where both contributed, run both actions without confusing them, because the tax judge cannot award damages against the notaire and the civil judge cannot discharge the tax.

Five practical reflexes will protect most British sellers. First, mandate the notaire in writing to send you the draft 2048-IMM-SD computation at least two weeks before signing, with the allowance table and the representative’s details shown. Second, deliver every invoice and both deeds in one indexed bundle, with translations of the key lines where the amounts are unclear, and keep the originals. Third, if you live in Britain and the price exceeds 150,000 euros, start the representative’s accreditation the week the offer is accepted, not the week of the signing. Fourth, align the French and British computations from day one: same sale price, same costs, same exchange-rate method, so the Foreign Tax Credit Relief claim in London mirrors the French base and HMRC has no reason to query it. Fifth, if anything looks wrong after signing, file the réclamation immediately and diary the two-month tribunal deadline from any rejection, because time limits in tax litigation are rarely extended and never for a sympathetic reason.

Conclusion

Selling a French second home after Brexit means accepting that France taxes first and taxes precisely: a 19% income-tax charge on the allowance-adjusted gain, social levies on a slower allowance clock running to thirty years, a possible 2% to 6% surtax on large gains, and collection at the signing table by a notaire who works from the papers you supply. It means recognising the two British-specific pressure points the case law and the code now mark clearly: the 150,000-euro former-resident shelter is reserved to European Union and European Economic Area nationals, and a vendor living in Britain who sells for more than 150,000 euros must fund and appoint an accredited tax representative who cannot be the notaire. It means using the treaty as it was designed, with France taxing the French gain under Article 14 and Britain granting credit under Article 24, rather than hoping one payment quietly settles both sides. And it means treating the social levies as definitively due for British-affiliated sellers after the Conseil d’État’s third-country decisions, instead of relitigating a European Union exemption that no longer covers you. Owners who internalise those four points, assemble their evidence early and have the draft computation checked before the deed is signed will usually find the bill predictable and the double-tax relief routine. Those who discover the representative rule, the thirty-year levies clock or the treaty-credit paperwork after signing will find every remedy slower and dearer. In this field, as in most Franco-British files since Brexit, the cheapest lawyer is the calendar: start early, prove everything, and challenge quickly when the figures are wrong.

Need a quick opinion on your case.

If you are selling a French property from Britain and want your capital-gains computation, treaty position or tax claim checked before you sign, our office offers a telephone consultation within 48 hours with a lawyer of the firm. Call +33 6 46 60 58 22 or write via our contact page with your deeds and the notaire’s draft: we will tell you what you owe, what you can save, and what to challenge.