You bought a stone farmhouse in the Dordogne or a flat in Paris years ago, you have settled in France since Brexit or you still live in Britain and keep a French second home. Then a letter arrives from the French tax office, or your notaire warns you at a family meeting: your property may fall within the French impots sur la fortune immobiliere, the annual tax on property wealth universally known as IFI. Many British owners have never heard of it, because the United Kingdom levies no equivalent annual tax on the value of your home. Others assume that the France-United Kingdom double tax treaty protects them, or that holding the house through a Societe Civile Immobiliere, the French property-holding company universally called a SCI, keeps them outside the tax. Both assumptions are dangerous, and recent French court decisions show taxpayers losing tens of thousands of euros on exactly those arguments. This guide explains, for a British reader, who pays IFI after Brexit, what counts towards the 1.3 million euro threshold, how to declare and value your property each spring, and how to challenge a bill you consider wrong. Every French term is explained when it first appears, and every decisive legal proposition is anchored to the exact statutory text or court decision quoted in the article.

I. Are you liable for French IFI on your French property after Brexit?

A. Where do you live? Your tax residence decides whether France taxes your worldwide property or only your French property

The starting point is Article 964 of the Code general des impots, the French general tax code. It provides: « Sont soumises à cet impôt, lorsque la valeur de leurs actifs mentionnés à l’article 965 est supérieure à 1 300 000 € ». In plain terms, IFI is an annual tax, assessed on the net value of your property assets on 1 January each year, and it bites only when that value exceeds 1,300,000 euros. Below the threshold you owe nothing and you file nothing for IFI purposes. Above it, the whole question becomes which of your assets France is entitled to count, and the answer turns entirely on your domicile fiscal, meaning your tax residence.

If you are tax resident in France, France counts everything: « Les personnes physiques ayant leur domicile fiscal en France, à raison de leurs actifs mentionnés au même article 965 situés en France ou hors de France. » A British retiree living year-round near Bergerac is therefore taxable on the Dordogne house and also, in principle, on any house still owned in Kent or in Spain. That worldwide scope surprises many newcomers, because British tax has no equivalent charge. There is, however, one mitigating feature for newcomers worth knowing. The same Article 964 continues: « les personnes physiques mentionnées au premier alinéa du présent 1° qui n’ont pas été fiscalement domiciliées en France au cours des cinq années civiles précédant celle au cours de laquelle elles ont leur domicile fiscal en France ne sont imposables qu’à raison des actifs mentionnés au 2°. Cette disposition s’applique au titre de chaque année au cours de laquelle le redevable conserve son domicile fiscal en France, jusqu’au 31 décembre de la cinquième année qui suit celle au cours de laquelle le domicile fiscal a été établi en France ». In other words, if you were not tax resident in France during the five calendar years before you moved over, then for your first five full years of French residence you are taxed like a non-resident, only on your French assets. A family that relocated from Manchester to Lyon in 2023 and kept a let flat in Leeds does not add the Leeds flat to its IFI base until that five-year window closes. This is a temporary shelter, not an exemption, and diaries matter: the clock runs to 31 December of the fifth year following the move. For the worldwide-computation side of that resident position, including how a retained British home enters the base and how the 75 percent ceiling works, see our companion guide: French Resident After Brexit? Your London Home Counts Towards France's IFI Wealth Tax.

If you are not tax resident in France, because you live in Britain and use the French place as a second home, France counts only your French assets. Article 964 taxes: « Les personnes physiques n’ayant pas leur domicile fiscal en France, à raison des biens et droits immobiliers mentionnés au 1° de l’article 965 situés en France et des parts ou actions de sociétés ou organismes mentionnés au 2° du même article 965 , à hauteur de la fraction de leur valeur représentative de ces mêmes biens et droits immobiliers. » So the London home is ignored, but the Provençal villa, including shares in the SCI that holds it, is fully in scope. Note the household mechanics too: « Sauf dans les cas prévus aux a et b du 4 de l’article 6, les couples mariés font l’objet d’une imposition commune. Les partenaires liés par un pacte civil de solidarité défini à l’article 515-1 du code civil et les personnes vivant en concubinage notoire font l’objet d’une imposition commune. » Married couples, PACS partners and cohabiting partners are taxed jointly, which means the 1.3 million euro threshold applies to the household pot, not to each person separately. Two British civil partners who each own half of a 1.5 million euro Paris flat are jointly above the threshold even though neither share alone exceeds it. Finally, timing is fixed by statute: « Les conditions d’assujettissement sont appréciées au 1er janvier de chaque année. » Sell on 2 January and you were taxable for that year; buy on 2 January and you were not. The official Service-Public guidance page describing the persons concerned confirms this architecture for the general public: Impôt sur la fortune immobilière (IFI) : personnes et biens concernés.

Three practical consequences follow for British owners. First, establish your tax residence position deliberately before you argue about values: a British passport and a UK address do not by themselves settle domicile fiscal, which depends on your home, your principal stay, your professional activity and the centre of your economic interests. Second, newcomers inside the five-year window should still measure their French assets against the threshold, because the shelter covers foreign assets only. Third, couples should aggregate before concluding they are safe. Each of these points is decided on 1 January facts, so a New Year move, marriage or purchase can change the next bill.

B. What counts towards the 1.3 million euros? Homes, SCI shares, usufruct rights and deductible debts

The base of the tax is defined by Article 965 of the tax code: « L’assiette de l’impôt sur la fortune immobilière est constituée par la valeur nette au 1er janvier de l’année ». Two words carry the weight: net value. You count what you own, minus qualifying debts, and the following paragraphs explain each building block in turn.

Directly owned houses and flats are the core. But most British buyers who took advice hold through a SCI, so the treatment of company shares matters enormously. Article 965 taxes shares only in proportion to the underlying French bricks: the base includes shares « à hauteur de la fraction de leur valeur représentative de biens ou droits immobiliers détenus directement ou indirectement par la société ou l’organisme ». If your SCI owns a 2 million euro villa in Cannes and 500,000 euros of cash and shares, only the property fraction of your shares counts. Conversely, you cannot hide the villa behind the company: the fraction follows the bricks wherever they sit in the chain. A striking illustration comes from the Tribunal judiciaire de Paris, 5 May 2026, RG 24/13163, concerning Dutch nationals, whose reasoning applies mechanically to British owners in the same position. The court recorded: « Ils détiennent, en leur qualité d’associés à 100%, la SCI [F] [S] qui est propriétaire d’un bien immobilier situé à Cannes et la SCI [H] ET COMPAGNIE qui est propriétaire d’un appartement sur la commune de Orcières. » After a paper audit of their IFI returns for 2018 to 2020, the administration issued corrections of 98,367 euros for 2018, 96,344 euros for 2019 and 94,338 euros for 2020, surcharge and late interest included. The owners argued « que la convention fiscale bilatérale franco-néerlandaise ne prévoirait pas l’imposition des biens incorporels de nature mobilière comme les parts de SCI qu’ils détiennent en France », in substance that a bilateral treaty shielded their company shares. The tribunal rejected the claim entirely: « DÉBOUTE M. [T] [H] et Mme [S] [Z] épouse [H] de leurs demandes », and ordered them to pay costs plus 2,000 euros under Article 700 of the Code of Civil Procedure. The lesson for a British owner holding a villa through a SCI is direct: treaty arguments against IFI on SCI shares have failed in court, and the shares are pulled back into the base by the property fraction. Readers who hold French property through more exotic vehicles, such as Anglo-Saxon trusts, face an even heavier disclosure regime, described in our companion guide: British Family Trust and France After Brexit: Declaring It, Paying IFI on It, Passing It On, and Challenging the Bill.

Split ownership, very common in Franco-British inheritance planning, follows its own rule. Article 968 of the tax code provides: « Les actifs mentionnés à l’article 965 grevés d’un usufruit, d’un droit d’habitation ou d’un droit d’usage accordé à titre personnel sont compris dans le patrimoine de l’usufruitier ou du titulaire du droit pour leur valeur en pleine propriété. » An usufruit is a lifetime right to use a property and take its income, while the nue-propriete, the bare ownership, belongs to someone else, typically the children. As a default, the usufructuary, the holder of the lifetime right, declares the full unencumbered value, and the bare owner declares nothing. Only narrow statutory exceptions, such as usufructs created by specific inheritance provisions, allow the value to be split according to the Article 669 scale. British parents who gave the bare ownership of the French house to their children while keeping the lifetime use must therefore check who actually bears the IFI line, because getting it backwards produces both an under-declaration by one party and a baseless declaration by the other.

Two reliefs then reduce the bill. First, the main home discount. Article 973 provides: « un abattement de 30 % est effectué sur la valeur vénale réelle de l’immeuble lorsque celui-ci est occupé à titre de résidence principale par son propriétaire. » An abattement is a statutory reduction, the valeur venale reelle is the open-market value, and the residence principale is the home where you actually and habitually live. Only one property per jointly taxed household can benefit. The Tribunal judiciaire de Nancy, 13 February 2026, RG 23/00802, shows how strictly the administration polices this relief: after a paper audit, it issued corrections « en remettant en cause le bénéfice d’un abattement pour résidence principale au titre des années 2020 et 2021, et en rehaussant la valeur de quotes-parts indivises détenues sur certains biens immobiliers au titre des années 2018 à 2021 ». The additional assessments, 22,587 euros collected in May 2022, were upheld in full after the taxpayer’s administrative complaint failed in January 2023. The administration relied on hard occupancy evidence: the income tax returns for 2019 and 2020 showed an address elsewhere, the taxpayer’s own letters admitted spending more time in another town for his wife’s health, and the business rates notices for his professional activity never mentioned the disputed flat. The tribunal therefore « DEBOUTE M. [H] [R] de l’intégralité de ses demande tendant à obtenir l’annulation de la décision de rejet de l’administration fiscale, la réduction de l’assiette d’imposition et la décharge des impositions supplémentaires IFI 2020 et 2021 ». For a British owner splitting life between a London pied-a-terre and a house in France, the message is blunt: the 30 percent relief follows genuine principal occupation, proved by tax returns, bills, insurance and daily-life evidence, not by assertion. Claiming it on a secondary residence is one of the fastest routes to a reassessment.

Second, debts reduce the net base. Article 974 allows: « Sont déductibles de la valeur des biens ou droits immobiliers et des parts ou actions taxables les dettes, existantes au 1er janvier de l’année d’imposition, contractées par l’une des personnes mentionnées au 1° de l’article 965 et effectivement supportées par celle-ci, afférentes à des actifs imposables ». Only loans linked to taxable property count: purchase prices, genuine repair and maintenance, improvement, construction and extension costs, and property taxes that are not normally the occupier’s burden. A mortgage taken to buy the French villa is deductible; a consumer loan or a loan for a yacht is not. The debt must exist on 1 January and be genuinely borne by you, and anti-avoidance rules disregard intra-group and self-dealing loans used to empty SCI balance sheets artificially. Keep bank statements showing the outstanding capital each 1 January, because the burden of proving the debt is yours.

Finally, French residents benefit from a ceiling, the plafonnement. Article 979 reduces IFI where IFI plus French and foreign income taxes exceed 75 percent of the previous year’s worldwide net income, with defined add-backs. Non-residents have no equivalent ceiling. And a closing warning on treaties: unlike income and capital gains, where the bilateral treaty allocates taxing rights and France grants credits, IFI is a standalone annual wealth tax with no foreign tax credit against it, and Britain offers no annual wealth tax to absorb it. Budget accordingly: the IFI line is a real cash cost every year the threshold is crossed, and it sits on top of taxe fonciere, the local property ownership tax, and any income tax on rents.

II. How do you declare, value and challenge French IFI as a British owner?

A. How do you declare and value your French property for IFI each spring?

Declaration is inseparable from the income tax return. Article 982 of the tax code states: « Les redevables mentionnent la valeur brute et la valeur nette taxable des actifs mentionnés à l’article 965 sur la déclaration annuelle prévue à l’article 170 » and attach schedules conforming to the administration’s template, listing and valuing each asset In practice you file form 2042-IFI and its schedules alongside your income return in spring, within the same deadlines as the income declaration, which run by zone and by online versus paper filing. The official filing guide confirms the mechanics: You must use form No. 2042-IFI, sent with its schedules to your tax office together with the income return, while non-residents without French income use the dedicated 2042-IFI-COV identification form. The calculation method, rates and scale are set out here: Calcul de l’impôt sur la fortune immobilière (IFI). Miss the return and the penalties examined below apply automatically, so diarise the spring campaign even in a year when you believe you have slipped below the threshold: the administration may disagree with your valuation, and a filed return with annexes is your first line of defence.

Valuation is where most British files succeed or fail. Article 973, paragraph I, adopts the inheritance-valuation standard: « La valeur des actifs mentionnés à l’article 965 est déterminée suivant les règles en vigueur en matière de droits de mutation par décès. » That points to open-market value on 1 January, proved by comparison with genuinely similar properties. The Cour d’appel de Nîmes, 13 February 2025, RG 23/03035, restated the test in terms every owner should memorise: « La valeur vénale d’un bien est constituée par le prix qui pourrait en être obtenu par le jeu de l’offre et de la demande dans un marché réel au jour de la mutation et elle est déterminée à partir d’une comparaison tirée de la cession de biens intrinsèquement similaires. » The case concerned a large development-land holding in southern France: the owners had declared the house at 525,000 euros after the main-home relief and the adjoining land at 7.6 million euros, then asked the court to cut the whole estate to 980,000 euros, arguing that the prospect of planning permission, on which the original value depended, had evaporated. The court refused and instead « Fixe au 1er janvier 2019 la valeur du tènement immobilier à [Localité 27] [Adresse 23] constitué de parcelles de terrain d’environ 70 000 m² dans l’actuelle zone 1AUc et 10 000 m² dans la zone actuelle A, le tout à prendre et à détacher d’une propriété de plus grande importance figurant au cadastre section AK n° [Cadastre 4] à [Cadastre 5], [Cadastre 7] à [Cadastre 8], [Cadastre 9], [Cadastre 10], [Cadastre 11], [Cadastre 12], [Cadastre 14], [Cadastre 15] et [Cadastre 16] pour une surface de 12ha 78a 21 ca à la somme de 5 219 556 euros pour l’imposition au titre de la fortune immobilière pour l’année 2019 », adding full costs of both instances and 3,000 euros under Article 700 against the taxpayers. Three lessons emerge. First, your own filed value binds you in practice: departing from it requires proof of exaggeration under strict conditions. Second, hope value linked to planning permission counts while the permission remains realistically available; bare assertions that the commune has turned hostile need documentary proof. Third, the administration wins with concrete comparables, recent sales of intrinsically similar local property, while taxpayers lose with distant or dissimilar references. Build your file the same way the administration builds its challenge: three to five notarised local sales of comparable size, condition, location and planning status within roughly eighteen months of 1 January, adjusted openly for differences, plus an agent’s written opinion kept on file. For SCI shares, apply the property fraction to that market value and keep the company balance sheet proving the ratio. For jointly owned shares in indivision, an undivided share, expect the administration to test your discount: the Nancy judgment above upheld uplifts on « la valeur de quotes-parts indivises détenues sur certains biens immobiliers », so any minority or illiquidity discount must be evidenced, not simply assumed.

British owners face two recurring valuation traps. The first is currency and anchoring: converting a 2019 sterling purchase price at today’s exchange rate, or clinging to the price paid a decade ago, is not a 1 January market valuation. Markets in the Luberon, Biarritz or the 7th arrondissement of Paris move on their own path, and the tax office uses local notarial databases that know it. The second is renovation asymmetry: owners add the cost of a new roof and pool to justify a higher asking price when selling, then plead dilapidation when the IFI return falls due. The file must be consistent year to year, because the paper audit, the controle sur pieces, compares your IFI annexes with your income return, your wealth declarations on other forms and the land registry. Photographs, like-for-like agency particulars, the diagnostic surveys from your purchase and a short annual note explaining movements in value turn a fragile estimate into a defensible position. Where the property includes development land, commission a planning note from the mairie or your architect before claiming that constructibility has been lost. And where the property is your genuine principal home, assemble the occupancy file early: income returns showing the address, utility bills, home insurance, medical registration and school records. The Nancy case shows that the administration checks the address on your income return first, and your own correspondence second.

B. How do you challenge an IFI bill, a valuation or a penalty?

Most IFI disputes begin quietly, with a paper audit. The administration writes, questions a value, denies the 30 percent relief or reinstates SCI assets, and issues a proposition de rectification, a reasoned proposal to correct the base. Reply within the deadline with evidence, because silence hardens the file and agreement narrows later remedies. If the correction is maintained and collected, two layers of challenge remain: the administrative complaint, the reclamation contentieuse, and then the court, the Tribunal judiciaire for IFI. The governing proof rule, recalled by the Nîmes court, is Article R.194-1 of the Livre des procedures fiscales, the procedural tax code: « Lorsque, ayant donné son accord à la rectification ou s’étant abstenu de répondre dans le délai légal à la proposition de rectification, le contribuable présente cependant une réclamation faisant suite à une procédure contradictoire de rectification, il peut obtenir la décharge ou la réduction de l’imposition, en démontrant son caractère exagéré. Il en est de même lorsqu’une imposition a été établie d’après les bases indiquées dans la déclaration souscrite par un contribuable ou d’après le contenu d’un acte présenté par lui à la formalité de l’enregistrement. » Discharge or reduction means cancelling or cutting the tax, and caractere exagere means you must demonstrate that the retained value exceeds the true market value. In practice this is a battle of comparables judged on the Nîmes test quoted above. The owners in Nîmes lost precisely because they could not prove, with similar local sales, that their self-declared figure was excessive, while the administration produced dated local transactions supporting 5,219,556 euros. Do not file a complaint that merely says the figure feels high; file one that substitutes a documented value for the administration’s value, comparable by comparable.

Time limits are strict and unforgiving. Article R.196-1 of the procedural 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 ; b) Du versement de l’impôt contesté lorsque cet impôt n’a pas donné lieu à l’établissement d’un rôle ou à la notification d’un avis de mise en recouvrement ». For IFI, count from collection or payment: tax put in recovery in 2025 must generally be challenged by 31 December 2027. The Nancy timeline illustrates the discipline: corrections collected on 13 May 2022, complaint filed 27 October 2022, rejection 16 January 2023, court action March 2023. Move early, because interest accrues while you argue and a late complaint is inadmissible however strong the valuation case. If the administration rejects the complaint, the Tribunal judiciaire hears the appeal, and adverse costs follow defeat, as each of the three decisions quoted here shows with Article 700 awards of 2,000 to 3,000 euros plus full costs.

Penalties stack on top of the principal. Article 1728 of the tax code punishes late or missing returns with surcharges of 10 percent without a formal demand or with filing within thirty days of one, 40 percent beyond that, and 80 percent for concealed activity, plus late interest. The Dutch-owned SCI case carried a 10 percent surcharge on each of the three years alongside interest, turning a valuation dispute into bills near 100,000 euros a year. Where the administration alleges deliberate misstatement, higher penalties and a longer recovery window enter the frame, so the cheapest dispute is the one avoided by a careful return. Three defences recur in successful files. First, the threshold defence: prove the 1 January net value, after qualifying debts and the lawful reliefs, at or below 1,300,000 euros, with the SCI fraction correctly computed. Second, the relief defence: establish genuine principal occupation with the Nancy-style paper trail, or proper usufruct allocation with the notarial deed. Third, the valuation defence: replace the administration’s comparables with better ones under the Nîmes test. What does not work, on current case law, is the blanket treaty defence for SCI shares. The Paris tribunal’s rejection of the Dutch-treaty argument is a warning to British owners tempted by the equivalent UK-treaty reasoning: IFI reaches the shares through the property fraction in Article 965 regardless of the wrapper, and a court will want to see valuation evidence, not architecture arguments. British guidance on living in France usefully reminds expatriates to organise their residence and tax position proactively: Living in France: official UK guidance. Read it alongside the French rules, not instead of them.

For owners in Paris and the Ile-de-France, two local accents deserve attention. First, valuations in the capital move street by street, and the administration’s notarial references are granular: a 17th-arrondissement Haussmann flat and a Seine-Saint-Denis new build are never comparable, so demand the office’s own references and answer them at the same level of detail. Second, high-value Paris files often combine IFI with rental-income or capital-gains questions on the same building, and consistency across returns is checked. The competent court for contesting an Ile-de-France assessment is the Tribunal judiciaire de Paris, the same court that decided the SCI-treaty case, which makes that judgment’s method directly relevant to Paris owners. Keep every IFI annex, comparable and receipt for at least the recovery period plus the dispute tail, because a challenge filed in year three will need year-one evidence.

Conclusion

French IFI is a tax that rewards method and punishes assumption. Check your residence position on 1 January, because it decides whether France counts your worldwide property or only your French property, and remember the five-year newcomer window. Aggregate the household, apply the SCI property fraction honestly, allocate usufruct values to the right person, evidence genuine principal occupation before claiming the 30 percent relief, and deduct only real property-linked debts existing on 1 January. Declare each spring on form 2042-IFI with full schedules, value by comparison with intrinsically similar local sales, and keep the file that proves it. If a correction arrives, answer with better comparables, observe the 31 December of the second-year complaint deadline, and argue valuation rather than treaty architecture, which the courts have rejected for SCI shares. Handled this way, IFI becomes a calculable annual cost rather than a frightening letter, and your French house remains what it should be: a home, not a dispute.