You signed the acte de vente in the notaire’s office, the keys changed hands, and before the price even reached your account a slice of it stayed in France. If you have just sold a French holiday home or a buy-to-let flat while living in Britain, or while living in France as a British national, that deduction is the French capital gains machinery doing its normal work. It is called the plus-value immobiliere, literally the property added value, and since Brexit it applies to you as a third-country seller. France taxes the gain because the bricks are on French soil. Britain taxes it again because you are its resident. The France-United Kingdom double tax treaty then decides which country keeps what, and both countries give you formal routes to challenge a bill that goes too far. This guide walks through each stage in plain English: what the notaire withholds on completion day, how the taxable gain is worked out, how the treaty splits the taxing rights between Paris and London, and how to contest an excessive assessment on either side of the Channel.

I. How France taxes the sale of your French second home after Brexit

A. What the notaire withholds on completion day and which papers prove the gain

The starting point is simple. French law provides that “les plus-values réalisées par les personnes physiques ou les sociétés ou groupements qui relèvent des articles 8 à 8 ter , lors de la cession à titre onéreux de biens immobiliers bâtis ou non bâtis ou de droits relatifs à ces biens, sont passibles de l’impôt sur le revenu dans les conditions prévues aux articles 150 V à 150 VH”. In ordinary language, any individual who sells a French building or land for money owes income tax on the gain. The statute is article 150 U of the Code general des impots, the French tax code, and it has applied in the same way since long before Brexit. What Brexit changed is your personal status in the eyes of that code: you are no longer a European Union national, so every favour the statute reserves for Union residents now has to be read without you in it.

The first question the notaire asks is therefore where you live for tax purposes. A notaire is not an English-style conveyancer. He or she is a French public officer who draws up the deed, collects the taxes on behalf of the state and can be held liable if the wrong amount is paid. French tax residence itself is defined by article 4 B of the tax code, which treats as French tax residents people who have their home, their main place of stay, their professional activity or the centre of their economic interests in France. If none of those connects you to France, you sell as a non-resident, and a different levy applies to you.

That levy is the prelevement, a withholding charge for non-residents set out in article 244 bis A of the tax code. It catches, in the words of the statute, “a) Les personnes physiques qui ne sont pas fiscalement domiciliées en France au sens de l’article 4 B”, meaning individuals who are not tax resident in France, and it applies, in the words of paragraph 3, to “Le prélèvement mentionné au 1 s’applique aux plus-values résultant de la cession : a) De biens immobiliers ou de droits portant sur ces biens”, meaning gains from selling buildings or rights over them. French-source income expressly includes property income of this kind: article 164 B of the tax code lists among revenues of French source the income from buildings situated in France and the capital gains defined by the non-resident provisions. So even if you have lived in Manchester for twenty years and only spent August in the Dordogne, the gain on your Dordogne house is French-source income and France taxes it first.

In practice you never calculate and pay this levy yourself. The tax is collected at the moment the deed is registered. Article 244 bis A, IV, of the tax code states that “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”, which means the tax due is paid when the deed is registered, or within a month of the sale if there is no registration, under the responsibility of a representative established in France and accredited by the tax administration. Your notaire prepares the computation on the official capital gains return, form 2048-IMM, deducts the tax from the sale price and pays it to the French Treasury on your behalf. The service-public.fr guidance for sellers confirms the mechanics: the official form 2048-IMM carries the computation table, and in practice the notaire fills it in.

Because the representative, called the representant fiscal, guarantees payment, non-resident sellers must normally appoint one. Again the official guidance is explicit: non-residents must appoint a tax representative whenever the gain is taxable, and that representative must hold an accreditation from the tax authorities with financial guarantees. There are exemptions, and the most useful one is automatic: no representative is needed where the sale price does not exceed 150,000 euros. So a small studio sold for 140,000 euros needs no accredited representative, while a 400,000 euro village house does. The notaire will tell you which side of the line you fall on and usually introduces an accredited firm.

One more check happens on completion day that surprises British sellers. The notaire must verify where your money comes from. The Cour de cassation, France’s supreme civil court, held in a published ruling of 22 May 2019, appeal number 18-12.101, that a notaire faced with an unusually complex file that leaves room for doubt about where the money comes from must verify the origin of the funds and file a report with Tracfin, the French anti-money-laundering unit, and that failing to do so is a disciplinary breach. The full decision is published at Cour de cassation, First Civil Chamber, 22 May 2019, No 18-12.101. For an ordinary British seller paid by bank transfer from a British high-street bank, this means answering a few questions about the source of the original purchase funds. Bring old bank statements if you still have them.

The sharpest boundary in the whole system is between a main home and everything else. The statute exempts “1° Qui constituent la résidence principale du cédant au jour de la cession”, meaning property that is the seller’s main residence on the day of sale. A French second home, a maison secondaire, is by definition never the main residence, so the exemption never applies to it. The courts enforce this strictly. In a decision of 20 October 2023, case 22PA00938, the Paris administrative court of appeal refused the exemption for part of a Paris building that had been let to a tenant until eleven days before the sale, holding that the seller had to prove the rooms were genuinely her main home on completion day. The judgment is published at CAA Paris, 20 October 2023, No 22PA00938. If your French house was let out, lent to friends or simply stood empty while your real life happened in Britain, it is a second home and the gain is taxable.

British sellers sometimes ask about the special relief for people who leave France, capped at 150,000 euros of gain. Read it carefully, because Brexit took it away from you. The statute grants it, under article 150 U, II, 2° of the tax code, only “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”, meaning only when the non-resident seller is a national of a European Union state or of a European Economic Area state covered by a tax assistance convention with France. A British passport no longer qualifies. A separate departure relief exists in article 244 bis A for someone who sells the house that was his French main residence when he moved abroad, but it demands a sale no later than 31 December of the year after the move, with the property never made available to third parties in between. A holiday home you kept for years after moving back to Britain meets none of these tests.

B. How your taxable gain is worked out: allowances, 19 per cent tax, social charges and the surtax

Once the notaire has established that your sale is taxable, the computation follows a fixed sequence. The gross gain is the simplest part. Article 150 V of the tax code states: “La plus ou moins-value brute réalisée lors de la cession de biens ou droits mentionnés aux articles 150 U à 150 UC est égale à la différence entre le prix de cession et le prix d’acquisition par le cédant.” The gross gain equals the sale price minus the purchase price. From the purchase price you may add the real acquisition costs, notaire fees and stamp duty, either at their actual amount or as a flat 7.5 per cent of the price, plus building works. Works must be proved with invoices from registered firms; do-it-yourself materials without proper bills are routinely rejected. From the sale price you subtract the costs of the sale itself, such as agency commission you paid and mandatory surveys. Keep every invoice from the purchase and from any renovation, because the notaire can only add what you can document.

The gross gain is then reduced by holding allowances, called abattements pour duree de detention, which reward long ownership. The allowance runs at a different speed for the income tax part and for the social charges part. The official service-public.fr table runs as follows: up to five years of ownership, no allowance on either base; from the sixth to the twenty-first year, 6 per cent per year off the income tax base and 1.65 per cent per year off the social charges base; in the twenty-second year, 4 per cent and 1.6 per cent; beyond the twenty-second year, the income tax base is fully exempt while the social charges base continues at 9 per cent per year; beyond the thirtieth year both are exempt. The same page summarises the outcome in plain terms: income tax ends after twenty-two years of ownership, and the social-charges exemption needs thirty years. A worked official example explains that a 10,000 euro gain on a property held ten years gets a 30 per cent income tax allowance, 6 per cent times five years, leaving 7,000 euros taxable, and an 8.25 per cent social charges allowance, 1.65 per cent times five years, leaving 9,175 euros subject to social charges. Count your holding period from the date on the old deed to the date on the new one.

The income tax rate itself is flat. Article 200 B of the tax code provides: “Les plus-values réalisées dans les conditions prévues aux articles 150 U à 150 UC sont imposées au taux forfaitaire de 19 %.” Gains of this kind are taxed at the flat rate of 19 per cent. For non-resident sellers the levy follows the same rate today. The current rate paragraph of article 244 bis A, III bis, of the tax code states that “Toutefois, 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 %”, meaning individuals pay the levy at 19 per cent. There is no higher British rate: the old surcharge that once hit sellers outside the Union is gone from the statute for individuals.

If anyone still tries to charge a British seller more than 19 per cent, the courts have already answered. The Conseil d’Etat, France’s supreme administrative court, ruled on 23 June 2022, case number 445785, on a levy charged at the old 33.33 per cent rate to a Swiss national living in Monaco who had sold a flat in Nice. The court recalled that article 63 of the Treaty on the Functioning of the European Union, as set out in the judgment, provides that “Dans le cadre des dispositions du présent chapitre, toutes les restrictions aux mouvements de capitaux entre les Etats membres et entre les Etats membres et les pays tiers sont interdites (…)”, meaning all restrictions on capital movements between member states and between member states and third countries are prohibited, and it held that Union law “faisait seulement obstacle à un prélèvement excédant le taux de 19 % applicable, en vertu des dispositions de l’article 200 B du code général des impôts, aux plus-values de même nature réalisées par les résidents de France, de l’Union européenne et des autres Etats parties à l’accord sur l’EEE ayant conclu avec la France une convention d’assistance administrative en vue de lutter contre la fraude et l’évasion fiscales”. The decision is published at Conseil d’Etat, 9th Chamber, 23 June 2022, No 445785. The reasoning protects you directly: the free movement of capital covers movements between the Union and third countries, and Britain is now a third country like Switzerland, so a levy above the 19 per cent benchmark is unlawful and the excess must be refunded.

On top of the 19 per cent come the prelevements sociaux, the social charges. Their base is set by article L136-6 of the social security code, and the official rate for property gains is confirmed in English by service-public.fr: social charges run at 17.2 per cent, so that a 20,000 euro taxable gain bears 3,440 euros. The combined French burden on a recent purchase is therefore 19 per cent plus 17.2 per cent, or 36.2 per cent of the gain after allowances, before any surtax. Non-residents sometimes hope to escape the social charges; the impots.gouv.fr international help pages treat that as a live dispute and even run a dedicated frequently asked question for non-residents whose Dreyer social-levy appeals are still pending, which shows claims in this area are common and slow.

Large gains attract one more layer, the surtaxe sur les plus-values elevees, a surtax on high gains created by article 1609 nonies G of the tax code. The statute opens with these words: “Il est institué une taxe sur les plus-values réalisées dans les conditions prévues aux articles 150 U et 150 UB à 150 UD par les personnes physiques”, meaning a tax is established on the gains covered by the main property-gains articles. It continues: “La taxe est due à raison des plus-values imposables d’un montant supérieur à 50 000 €, selon le barème suivant appliqué au montant total de la plus-value imposable”, meaning the tax is due on taxable gains above 50,000 euros on a sliding scale applied to the whole gain. The scale runs from 2 per cent between 50,001 and 100,000 euros up to 6 per cent above 260,000 euros, with smoothing where each band starts. A 120,000 euro taxable gain costs 3 per cent, or 3,600 euros, on top of everything else. The notaire computes it on the same 2048-IMM return.

A practical example ties the sequence together. Suppose you bought a two-bedroom flat in Nice in 2015 for 250,000 euros and sell it in 2026 for 340,000 euros after ten years of ownership. The gross gain is 90,000 euros. The income tax allowance of 30 per cent leaves 63,000 euros taxed at 19 per cent, or 11,970 euros. The social charges allowance of 8.25 per cent leaves about 82,575 euros taxed at 17.2 per cent, or about 14,203 euros. The taxable gain of 63,000 euros exceeds 50,000 euros, so the surtax adds 2 per cent, or 1,260 euros. The French bill is roughly 27,400 euros, withheld by the notaire on completion day. Whether that is the end of the story depends on London, which is where the treaty comes in.

II. How a British seller avoids paying twice and challenges the bill

A. What the France-United Kingdom treaty lets each country tax and how to claim relief at home

France and Britain signed their current double tax treaty, called a convention fiscale, on 19 June 2008, and it was published in France by decree 2010-20 of 7 January 2010. The full official text is available at Decree No 2010-20 of 7 January 2010 publishing the France-United Kingdom tax convention of 19 June 2008. Its capital gains article gives France the first right to tax your sale: gains from selling immovable property situated in one of the two states are taxable in that state, as set out in Article 14, paragraph 1 of the convention. Your Nice flat is taxable in France. That rule is the legal foundation of everything the notaire withheld.

The treaty does not give France the exclusive right, so Britain may tax the same gain if you are its resident. The British government’s own guidance confirms the position openly: United Kingdom residents pay Capital Gains Tax when they dispose of overseas property, may also have to pay tax in the country where the gain arose, and may be able to claim relief if they are taxed twice. See the official GOV.UK page Selling overseas property. In practice a British resident declares the French sale on the foreign pages of the Self Assessment tax return, computes the British gain under British rules, which allow different deductions and a different exempt amount, and then claims Foreign Tax Credit Relief for the French tax. The relief is capped: Britain credits the French tax only up to the amount of British tax on the same gain, so you always pay the higher of the two bills but never both added together.

The treaty’s elimination article organises that credit in both directions. For British residents it provides, in Article 24, paragraph 1(a) of the convention, that French tax lawfully charged under the treaty, including tax collected by withholding, counts as a credit against British tax computed on the same gains. Keep the notaire’s 2048-IMM return, the deed of sale and the French payment receipt: HM Revenue and Customs will ask for proof of the exact French tax before allowing the credit.

If instead you are tax resident in France when you sell, the mirror image applies. France taxes your worldwide gains and gives a credit for the British tax, but only for the gains the treaty lets Britain tax and only up to the French tax on the same income. The treaty states, in Article 24, paragraph 3(a)(ii) of the convention, that for gains covered by paragraphs 1, 2 and 6 of Article 14 the credit equals the British tax paid under those articles, capped at the corresponding French tax. Declare the sale on your French income tax return the following spring, attach the British computation, and claim the credit there.

Two traps deserve special attention. The first is the treaty rule for shares rather than bricks. Under Article 14, paragraph 2 of the convention, gains on shares, units or rights that derive most of their value from immovable property are likewise taxable where the property sits. If you hold your French house through a societe civile immobiliere, the French property company most British families use, selling the company shares is taxed in France just like selling the house. The Cour de cassation confirmed the same situs logic for French property held through domestic property companies in a ruling of 2 April 2025, appeal number 23-14.568, published at Cour de cassation, Commercial Chamber, 2 April 2025, No 23-14.568. Do not assume a share sale escapes the notaire and the levy; it does not.

The second trap is the treaty’s six-year tail. The treaty also contains a six-year tail: Article 14, paragraph 6 of the convention preserves each state’s right to tax gains made by someone who is resident there at the time of the sale, or who was resident there at any point in the previous six tax years. A seller who left Britain for France four years ago and sells the old family house, or who left France for Britain recently, can therefore face a lawful claim from the former home state as well as the current one. The credit mechanism still prevents true double taxation, but it doubles the paperwork: two returns, two computations, one credit claim. Diarise the six-year window before you assume the old country has lost interest.

The order of operations for a British resident seller is therefore fixed. First, the notaire withholds the French tax and gives you the 2048-IMM. Second, you report the disposal to HM Revenue and Customs. For British residential property the deadline is famously sixty days, and for foreign property the disposal goes on the Self Assessment return for the year of sale, with payment through the usual balancing process. Third, you claim Foreign Tax Credit Relief with evidence of the French payment. Fourth, if either bill looks wrong, you challenge it, which is the subject of the next section. Miss the second step and you risk British penalties even though the French tax was correctly paid; miss the third and you pay twice for no reason.

B. How to challenge an excessive French bill or a refused UK credit, step by step

Start with the French side, where the procedure is codified and the deadlines are strict. The foundation is article L190 of the Livre des procedures fiscales, the tax procedure code, which provides: “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.” Claims about taxes assessed or collected by the administration belong to the contentious jurisdiction when they seek to correct errors in the base or the calculation, or to obtain the benefit of a statutory right. A wrong allowance, a forgotten acquisition cost, an unlawful surcharge or a treaty credit denied all fit that definition.

You must complain to the tax office before you go to court. Article R*190-1 of the procedure code states: “Le contribuable qui désire contester tout ou partie d’un impôt qui le concerne doit d’abord adresser une réclamation au service territorial, selon le cas, de la direction générale des finances publiques ou de la direction générale des douanes et droits indirects dont dépend le lieu de l’imposition.” A taxpayer who wishes to dispute a tax must first send a claim to the local office of the tax administration for the place of taxation. For a property sale that is the tax office where the property sits, usually the service des impots des particuliers non-residents at Noisy-le-Grand if you live abroad. File online through your espace particulier on impots.gouv.fr where possible, and always keep proof of sending.

The deadline is the one sellers miss most often. Article R*196-1 of the procedure code provides: “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”. Claims must reach the administration by 31 December of the second year after the year of assessment or collection. Sell in March 2026 and the claim must arrive by 31 December 2028. A claim posted on 2 January 2029 is inadmissible however strong the merits, and the courts enforce this without mercy. Mark the date on completion day.

If the administration rejects your claim in whole or in part, or stays silent for six months, which counts as an implied rejection, you can take the case to the administrative court. Article L199 of the procedure code states: “En matière d’impôts directs et de taxes sur le chiffre d’affaires ou de taxes assimilées, les décisions rendues par l’administration sur les réclamations contentieuses et qui ne donnent pas entière satisfaction aux intéressés peuvent être portées devant le tribunal administratif”, meaning decisions on contentious claims that do not fully satisfy the taxpayer may be brought before the administrative tribunal. The competent court is the tribunal administratif for the property’s location. You have two months from the rejection notice to file. Ask in the alternative for discharge of the excess, called decharge, and for a refund with late-payment interest, and attach the deed, the 2048-IMM, the allowance computation and the treaty articles you rely on.

Three French arguments work best for British sellers. First, the arithmetic argument: the notaire’s computation omitted acquisition costs, works invoices, agency fees or years of ownership. Rebuild the computation line by line and claim the difference. Second, the 19 per cent ceiling argument from the Conseil d’Etat decision of 23 June 2022 discussed above: any levy above 19 per cent on an individual seller breaches the free movement of capital, and the excess must be refunded with interest. Third, the social charges argument: depending on your affiliation to a social security system and the latest case law, the 17.2 per cent may be partly challengeable. This last route is heavily fact-dependent and heavily litigated, as the impots.gouv.fr international pages show by maintaining a dedicated question for non-residents whose Dreyer social-levy appeals remain unprocessed. File the protective claim before the 31 December deadline even if the legal outcome is uncertain, because a claim filed in time preserves your rights while the courts settle the point.

On the British side the challenge runs through HM Revenue and Customs. If your Foreign Tax Credit Relief is refused or cut down, the refusal letter tells you how to respond: ask the officer to reconsider with the French evidence, request an internal review, and appeal to the Tax Tribunal within the time limit printed on the notice. The most common refusals have practical causes rather than legal ones. The French tax certificate is missing or illegible, so have the notaire issue a clear attestation of the tax paid with the 2048-IMM reference. The gain was computed differently in each country, so reconcile the two computations and show that the credit claimed never exceeds the British tax on the same gain. The disposal was reported late, so correct the return before HM Revenue and Customs opens an enquiry. Keep copies of everything for six years, which matches the treaty’s six-year tail and covers both countries’ enquiry windows.

When both countries insist they are right and the credit does not close the gap, the treaty offers a final route: the mutual agreement procedure, by which the French and British competent authorities negotiate your case between themselves, with arbitration if they cannot agree. It is slow, usually measured in years, but it costs nothing to request and it suspends neither country’s collection. Mention it in your French claim and in your British appeal as a fallback, and use it when the same gain is genuinely taxed twice because the two computations cannot be reconciled. Most cases never need it: a well-documented French claim plus a clean British credit claim resolves the bill.

Conclusion

Selling a French second home after Brexit means accepting that France taxes first and Britain taxes second, with the treaty preventing the total from exceeding the higher of the two. The French sequence is mechanical: the notaire establishes the gain, applies the holding allowances that exempt the income tax base after twenty-two years and the social charges base after thirty, withholds 19 per cent income tax plus 17.2 per cent social charges plus any surtax above 50,000 euros, and pays the Treasury on registration of the deed. Your protection lies in the paperwork you hand over before completion: the old deed, the acquisition costs, every works invoice, the proof of each year of ownership and, if the price exceeds 150,000 euros, the accredited representative’s details. The British sequence is declarative: report the disposal, compute the gain under British rules and claim Foreign Tax Credit Relief with the French receipts. Your protection there is the same discipline: one file, both computations, all receipts. And when either administration gets it wrong, the remedies are real but time-limited: a French claim by 31 December of the second year after the sale, then the administrative court within two months, and a British review or tribunal appeal within the deadline on the notice. The Conseil d’Etat has already drawn the outer boundary for third-country sellers at 19 per cent, the treaty has fixed France’s right to tax French bricks and Britain’s duty to credit the French tax, and the rest is method. Sell methodically, keep every paper, and challenge anything above what those texts allow.

Need a quick opinion on your case

Our firm offers a telephone consultation within 48 hours with an avocat of the chambers, for a rapid review of your sale file, your 2048-IMM computation and your treaty relief position. Call +33 6 46 60 58 22 or write through our contact page with your deed of sale and your notaire’s computation attached.