You bought the stone farmhouse in the Dordogne, or the flat near Antibes, years ago. Then a letter arrives from the French tax authority, headed impôt sur la fortune immobilière, the French tax on real-estate wealth universally known by its initials IFI, demanding several thousand euros. You live in Kent, you pay your UK tax, and you assumed that owning one French holiday home could not make you liable to a French wealth tax. For many British owners, that assumption is the most expensive mistake in the file. Since Brexit, British nationals are third-country nationals in France. The IFI itself was not created by Brexit, but Brexit removed the European safety nets some British owners once relied upon, and the French tax authority (the direction générale des finances publiques, usually shortened to DGFIP) now taxes British-owned French property without any EU-law discount. This article explains, in plain English, who falls within the charge, what counts towards the 1.3 million euro threshold, how to declare and value the property without overpaying, and how to challenge the bill when it is wrong, with the exact legal texts and court decisions you need.

I. Do You Actually Fall Within the French IFI Charge After Brexit?

A. Are You Even in the Net: Where You Live, What You Own, and the 1.3 Million Euro Line

The starting point is Article 964 of the French General Tax Code (the code général des impôts, the single statute that contains most French tax rules). Its opening words leave no doubt about the nature of the tax: Il est institué un impôt annuel sur les actifs immobiliers désigné sous le nom d’impôt sur la fortune immobilière. In English: an annual tax is established on real-estate assets, called the tax on real-estate wealth. The same article then sets the entry ticket: Sont soumises à cet impôt, lorsque la valeur de leurs actifs mentionnés à l’article 965 est supérieure à 1 300 000 €, meaning that only taxpayers whose assets described in Article 965 are worth more than 1,300,000 euros are liable. Below that line, there is nothing to pay and, as a non-resident, nothing to declare for IFI purposes. Above it, the whole net taxable estate is charged on a progressive scale, not merely the slice above the threshold.

Your residence position decides which of your assets France may count. If your domicile fiscal, your tax residence, is in France, the rule is worldwide: 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 national who has settled in France and become French tax-resident therefore faces IFI on French and non-French real estate alike, including a buy-to-let flat kept in Manchester. There is one soft landing for newcomers. Taxpayers who were not French tax-resident during the five calendar years before settling in France are taxed only on French-situated assets for five years: les personnes physiques 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°. A British family moving from Surrey to the Paris region in 2025 and becoming French tax-resident therefore counts only its French property until the end of 2030, which is a genuine planning window worth diarising.

If you stayed in the United Kingdom and merely own the French house, France taxes only what sits in France. The official service-public.fr page for taxpayers whose tax residence is abroad lists exactly three baskets: Biens et droits immobiliers possédés en France détenus par votre foyer, then shares in property companies holding French real estate, then shares in property companies holding real estate inside and outside France, but only in proportion to the French part. Your London home, your UK savings and your pension never enter the French calculation. What does enter it, apart from the house itself, catches many British owners by surprise: shares in a société civile immobilière, the French family property company universally called an SCI, which many British families were advised to create when buying, count towards the threshold in proportion to the underlying French bricks. Article 965 says so directly: Des parts ou actions des sociétés et organismes établis en France ou hors de France appartenant aux personnes mentionnées au 1° du présent article, à hauteur de la fraction de leur valeur représentative de biens ou droits immobiliers détenus directement ou indirectement par la société ou l’organisme. An English holding structure does not hide the French house from the IFI; even a UK company is looked through to the French property underneath. The same article aggregates the household, the foyer: De l’ensemble des biens et droits immobiliers appartenant aux personnes mentionnées à l’article 964 ainsi qu’à leurs enfants mineurs, lorsqu’elles ont l’administration légale des biens de ceux-ci. A married couple is therefore assessed jointly on the French portfolio, and the house cannot be split artificially between spouses to duck under the line.

The decisive date is always 1 January of the tax year. Article 965 defines the base as L’assiette de l’impôt sur la fortune immobilière est constituée par la valeur nette au 1er janvier de l’année. If you completed the purchase in March 2026, you are not liable for 2026 on that house; you become liable for 2027 on its value at 1 January 2027. Conversely, if you sold in February 2026, you still owe 2026 on the 1 January 2026 value because you owned it on the snapshot date. Market movements during the year are irrelevant, which is why the valuation evidence you gather must always be anchored to 1 January.

One honest warning about the double tax treaty. The British government guidance for its nationals in France states that The UK has a double taxation agreement with France so that you do not pay tax on the same income in both countries. Note the word income. That agreement deals with income tax and gains; it does not give a British non-resident any credit or exemption against the French IFI on a French-situated house. Do not assume your UK self-assessment return settles the French position. The two systems run in parallel, and the French one taxes the French bricks on its own.

Related reading in this British-desk series explains the wider property-tax picture for second homes, including the annual local taxes that sit alongside the IFI: British Second Home in France: 90/180-Day Rule, Overstay Bans and Long-Stay Visas After Brexit is part of the same cluster, and the property-tax companion piece on rental and occupation taxes completes it. Keep the IFI distinct from those yearly bills: the IFI is a national wealth tax with its own return, its own threshold and its own challenge procedure.

B. What Counts Towards the Threshold, and Which Debts Genuinely Reduce It

Not every euro of French property value is taxable, and not every debt is deductible. The exempt business-asset rules matter to British owners who run a genuine enterprise from their French property. Article 966 provides that Pour l’application de l’article 965, n’est pas considérée comme une activité industrielle, commerciale, artisanale, agricole ou libérale l’exercice par une société ou un organisme d’une activité de gestion de son propre patrimoine immobilier. Simply managing your own French rentals through a company is not treated as a real business, so the properties stay in the IFI base. A genuinely commercial furnished-letting operation can escape the charge, but the bar is high, as a British couple learned before the transfer from the old solidarity tax to the IFI. In a judgment of 19 June 2025 (case number RG 23/10575), the Bobigny court recorded the rule then in force as follows: les personnes physiques n’ayant pas leur domicile fiscal en France sont soumises à l’impôt sur la fortune à raison de leurs biens situés en France dont la valeur est supérieure à 1300000 € et qui n’ont pas de caractère professionnel. The couple, resident in the United Kingdom and taxed on a 58,469 euro solidarity-tax assessment for 2017, argued their furnished lettings were professional assets. The court rehearsed the three conditions for professional furnished letting, noted that their activity was loss-making and that they drew no French-taxable income from it, and dismissed the claim. The sting in the reasoning deserves quotation because it governs how French judges treat administrative guidance: L’emploi de l’expression prépondérance des recettes par la doctrine administrative ne saurait dénaturer une loi parfaitement claire. Where the statute is clear, creative readings of tax-office guidance will not save you. British owners declaring French holiday lets should therefore assume the properties count towards the 1.3 million euro line unless all three professional-letting conditions are genuinely met with French-taxable profits to show.

Family ownership splits need equal care. Many British parents holding a French house grant the bare ownership to their children while keeping the lifetime use, a split the French call démembrement between usufruit (the lifetime right to use the property or take its income) and nue-propriété (the bare ownership that becomes full ownership when the life interest ends). Article 968 allocates the tax burden bluntly: 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. The parent keeping the life interest is taxed on the full unencumbered value, and the children holding the bare ownership add nothing for that house. Splitting ownership between generations therefore does not split the IFI bill, except in the narrow statutory cases such as a surviving spouse’s life interest, where the code apportions between life tenant and bare owner by fixed statutory proportions. Take advice before restructuring: a gift of the bare ownership meant to reduce exposure can leave the donor parent taxed exactly as before.

Debts are where British owners most often overpay, in both directions. The official calculation page states the base plainly: the IFI is computed on the net value of the taxable estate au 1er janvier 2026, c’est-à-dire après déduction des dettes existantes à cette date, à condition de pouvoir les justifier. Only debts that exist at 1 January, and that you can prove, reduce the base. The outstanding capital of the French mortgage used to buy the house qualifies. A vague family loan with no written terms, an overdraft cleared before year-end, or a debt you cannot document does not. The leading court authority on deductible debts, decided under the former solidarity tax but on a mechanism identical to the IFI’s 1 January snapshot, is the Commercial Chamber of the Court of Cassation, 13 March 2019, appeal number 17-13.305. The court held: pour être déductible de l’assiette de l’ISF, une dette doit être certaine au jour du fait générateur de l’impôt, soit au 1er janvier de l’année d’imposition, et qu’une dette, incertaine du fait d’une contestation, est rétroactivement déductible pour le montant ultérieurement arrêté par la décision mettant fin à la contestation. Three lessons flow from that single sentence. First, certainty is judged at 1 January, not with hindsight. Second, a disputed debt is not lost forever: once the court fixes its amount, it becomes retroactively deductible for the years when it was uncertain. Third, keep the judgment, because the refund claim for the earlier years will depend on it. For IFI purposes the reasoning transfers directly, since Article 965 uses the same 1 January taxable event.

Related-party borrowing faces extra statutory suspicion. For company-held property, the code provides that Pour la valorisation des parts ou actions mentionnées au 2° de l’article 965, ne sont pas prises en compte les dettes contractées directement ou indirectement, par une société ou un organisme in the listed intra-group and family configurations. British families who finance an SCI with loans from their own UK company or from relatives should therefore expect the DGFIP to disallow the debt and should structure borrowing through genuine third-party bank finance wherever possible.

II. How Do You Declare, Value and Pay, Then Fight the Assessment When It Is Wrong?

A. How to Declare the House and Value It Without Overpaying: Returns, Evidence and the Rate Scale

Declaration is not optional once you cross the line, and it rides on the income-tax return. Article 982 provides that 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 adds that Ils joignent à cette déclaration des annexes conformes à un modèle établi par l’administration, sur lesquelles ils mentionnent et évaluent les éléments de ces mêmes actifs. In practice, that means the IFI annexes to the yearly income return filed each spring, with both the gross and the net taxable values stated property by property. Non-residents file through the non-resident tax office with the same annexes. Couples file jointly, and cohabiting partners declare the combined household on one of the two returns. Missing the return does not make the tax disappear; it exposes you to late-filing penalties and interest on top, and it starts no limitation clock in your favour.

Valuation follows the death-duty rules, which surprises British owners expecting a council-tax-style banding. The code states that La valeur des actifs mentionnés à l’article 965 est déterminée suivant les règles en vigueur en matière de droits de mutation par décès, meaning the open-market value, the valeur vénale, what a willing buyer would pay a willing seller on 1 January. There is exactly one statutory discount, and it almost never helps a British second-home owner: 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. The 30 per cent reduction applies only to the owner’s main residence. A holiday home in Provence occupied six weeks a year gets no abatement at all, and a Paris flat where you live full-time gets it on one property only. Many British files go wrong here in both directions: some claim the 30 per cent on a maison secondaire and invite reassessment with penalties, while others undervalue without evidence and cannot defend the figure when challenged.

The Paris court’s judgment of 19 January 2024 (case number RG 22/08190) is the clearest modern guide to what valuation evidence actually survives contact with the tax authority. The taxpayer owned two joined flats in Paris used as his main home, had declared IFI for 2019 to 2021, then claimed he had overvalued the property and sought a refund of 8,137 euros. The court rejected everything. Its reasons are a checklist written in reverse. Comparable sales used after the taxable event are worthless: the court held that the sale agreement of 17 December 2022 and the completed sale of 2 March 2023 sont postérieurs aux faits générateurs des impositions au titre de l’IFI et sont donc inopérants. A later sale at a lower price proves nothing about the 1 January value. Averages prove nothing either: an update report that merely quoted average prices per square metre without genuine comparables drew, in the court’s phrase, peremptory conclusions from means. And the income method, valuing by capitalising a hypothetical rent, ne peut être utilisée pour évaluer des immeubles qui ne sont pas loués, cannot be used for buildings that are not let. The court concluded bluntly: M. [O] n’établit pas le caractère erroné de l’évaluation de la valeur vénale de son bien tel que déclarée initialement à l’administration fiscale. The burden is on the taxpayer to prove the declared value wrong, with pre-1-January comparables of genuinely similar properties, precisely located and described, not with post-event bargains or neighbourhood averages. For a British owner, the practical lesson is to commission the notaire’s valuation or an expert report anchored before each 1 January, keep the comparable deeds, and never file a figure you could not defend with those papers.

Once the net taxable value is settled, the arithmetic is mechanical. The rate table in Article 977 runs from zero below 800,000 euros, 0.50 per cent up to 1.3 million, 0.70 per cent to 2.57 million, 1 per cent to 5 million, 1.25 per cent to 10 million and 1.50 per cent above, and the official calculation page reproduces the same scale with worked examples. Just above the threshold, a smoothing relief, the décote, softens the entry: for estates between 1.3 and 1.4 million euros, the tax computed on the scale is reduced by une somme égale à 17 500 €-1,25 % P, où P est la valeur nette taxable du patrimoine. The official page confirms the formula in identical terms: 17,500 euros minus 1.25 per cent of the net taxable value. So a British owner with a net French estate of 1,350,000 euros does not pay the full scale charge; the décote absorbs most of it. Charitable owners have a further lever. Article 978 allows the taxpayer to set against the IFI dans la limite de 50 000 €, 75 % du montant des dons en numéraire et dons en pleine propriété de titres de sociétés admis aux négociations sur un marché réglementé français ou étranger effectués au profit of qualifying research bodies, recognised public-interest foundations and similar donees. Cash gifts to an eligible French foundation therefore cut the IFI at 75 cents in the euro up to 50,000 euros of tax, which is far more generous than the income-tax equivalent and worth building into year-end giving.

B. How to Challenge the Bill: Reclaims, Deadlines, Evidence and the Court That Decides

Start with the paper, not the panic. Read the avis d’imposition, the formal assessment notice, line by line: the taxed persons, the properties included, the gross and net values, and the year concerned. The most common British-file errors are including a property sold before 1 January, counting the London home, forgetting to deduct the French mortgage balance at 1 January, claiming the 30 per cent main-home reduction on a holiday house, or valuing on a post-January sale. Each of those is a factual error the reclaim procedure is designed to fix. The official service-public.fr guide to tax disputes confirms the route into a formal challenge: Vous contestez le bien-fondé ou la régularité de votre impôt ? Vous pouvez déposer une réclamation. A wrong valuation, a forgotten debt or a misapplied threshold all qualify as disputes over the basis or the calculation of the tax. The same guide adds that the administration must answer within six months, and that you may then take the matter to the courts, while a deferral of payment (the sursis de paiement) can be requested in the meantime. File the réclamation, the formal contentious claim, with the tax office that issued the assessment, in writing, setting out the facts, the legal basis and the precise corrected figures, and attach the proof: loan statements at 1 January, the notaire’s valuation, the comparable deeds, the UK-residence evidence if domicile is disputed.

The deadline is strict and short enough to kill careless files. Article R*.196-1 of the procedures book provides that 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 decembre de la deuxieme annee suivant celle of the recovery or payment event it then details. For an IFI assessment collected in 2026, the claim must reach the administration by 31 December 2028 at the latest. Miss that date and the merits no longer matter; the claim is inadmissible. Diarise it on receipt of every assessment, because British owners who discover the problem when selling, often years later, regularly find the reclaim window shut. If the administration rejects the claim expressly or stays silent for six months, the dispute moves to the tribunal judiciaire, the ordinary civil court that hears IFI cases, as the Paris and Bobigny judgments show. Proceedings are in French, in writing, and evidence-led: the taxpayer proves the correct value, as the Paris court’s dismissal for unproven overvaluation demonstrates. Interest on refunds runs in the taxpayer’s favour under the procedures book, and claimants routinely invoke Article L.208 for moratory interest from the payment date, as the Paris taxpayer did for his 8,137 euros. Ask for it expressly in the claim and again before the court; it is not added automatically.

Three evidence rules decide most cases before they start. First, anchor every comparable before 1 January of the tax year, with deeds or agent records showing similar size, condition and micro-location; post-January sales are, in the Paris court’s word, inoperant. Second, prove debts with bank statements at 1 January and the loan offer, and keep any later court judgment fixing a disputed debt, since the Cassation ruling makes it retroactively deductible once fixed. Third, if domicile is in play, assemble the full residence file at once: flight and ferry records, utility bills, children’s schooling, GP registration, days-count diary and the UK statutory residence position, because the DGFIP will test French tax residence against conduct, not declarations. Where the file turns on a genuinely professional letting, prepare the three Bobigny conditions with French-taxable profit evidence, not bare turnover, before claiming any exclusion.

Finally, mind the clock on the administration’s side without relying on it. French tax law gives the authority a general right to reassess within defined periods, and an undeclared IFI liability does not improve with age. Voluntary correction through a reclaim or an amended position almost always costs less than a reassessment built by the tax office with penalties. If the assessment has already arrived, challenge it on time, on paper and with numbers. If it has not, and you suspect past years were declarable, regularise before the notice lands. Either way, the governing logic is the same: the IFI taxes French bricks held at 1 January above 1.3 million euros net, debts count only if certain and proven, valuations count only if evidenced before the snapshot date, and every challenge lives or dies on its deadline.

Conclusion

A British owner of a French second home is not exempt from the IFI by virtue of living in the United Kingdom, paying UK tax, or holding through a British or French company. The charge bites on French-situated property above 1,300,000 euros net at 1 January, wherever the owner lives and whatever wrapper holds it. The defences that work are concrete and documented: proving the estate sits below the threshold, deducting only certain and provable debts, valuing with genuine pre-January comparables, using the main-home reduction only where it truly applies, claiming the entry-year décote and, where relevant, the charitable-gift offset. The challenges that fail are the ones the courts have already rejected: post-event sale prices, neighbourhood averages, income-method valuations of unlet houses, professional-letting claims without French-taxable profits, and guidance-based arguments against a clear statute. Brexit changed the owner’s status, not the tax. Read each assessment on arrival, check the 1 January position, gather the proof early, and file any reclaim well before 31 December of the second following year. Done that way, the IFI becomes a manageable annual exercise rather than a nasty surprise in the post.

Need a quick opinion on your case

If you have received an IFI assessment on your French property, or you are unsure whether you must declare this year, speak to us before the deadline passes. We offer a telephone consultation within 48 hours with a lawyer of the firm. Call +33 6 46 60 58 22 (Maître Reda Kohen) or write via our contact page. We act for British owners across France, in English, from valuation and declaration through reclaims and court appeals.