You bought the stone farmhouse in the Dordogne years ago, or the flat in Paris that has quietly doubled in value. You live in London, Manchester or Edinburgh, you spend summers in France, and French tax never seemed your problem beyond the local property bills. Then a letter arrives, or your notaire (the French conveyancing solicitor who handles property and estates) asks an innocent question: what is your French property worth today? If the answer is anywhere near 1.3 million euros net, France’s wealth tax on property, the impôt sur la fortune immobilière (IFI), may already apply to you, whether you live in France or in Britain. This article explains who pays IFI after Brexit, which assets count and how they are valued, how the bill is worked out with a full numerical example, what reliefs cut it down, and exactly how British owners challenge an inflated valuation, with the three court decisions that organise the fight.
I. Do You Owe France’s IFI Wealth Tax on Your French Home After Brexit?
A. Who pays IFI: French residents, British residents and the five-year newcomer rule
The IFI is an annual tax on property wealth. Article 964 of the French General Tax Code provides, in its exact words, that “Sont soumises à cet impôt, lorsque la valeur de leurs actifs mentionnés à l’article 965 est supérieure à 1 300 000 €”: first, individuals whose tax home (domicile fiscal) is in France, on their property assets in France and abroad; second, individuals whose tax home is outside France, on their French buildings, land and rights plus the shares of companies to the extent those shares represent French property. The official service-public guidance confirms the split in plain terms: if your tax home is in France, everything counts worldwide; if it is abroad, only what sits in France counts, including shares in property companies that hold French buildings, apportioned to the French part (see who is liable and on what).
Three consequences follow for British readers. First, a British tax resident who keeps a holiday home in France is inside the French net on that home as soon as the net taxable value tops 1,300,000 euros. Residence in the United Kingdom after Brexit changes nothing here: the charge attaches to the French bricks, not to your passport. Second, a British family that moved to France and became French tax resident is taxed on worldwide property, including a retained flat in London, subject to the five-year newcomer rule described below. Third, liability is assessed household by household (foyer): married couples are taxed jointly, and so are partners in a pacte civil de solidarité (PACS, the French registered civil partnership) and couples in acknowledged cohabitation (concubinage notoire), while the property of minor children under legal administration is added to the parents’ base. If you own the French house jointly with a spouse or partner, there is one threshold for the household, not one each.
The five-year newcomer rule deserves attention because it is the one deliberate soft landing the statute offers. The same Article 964 states that individuals who were not French tax resident during the five calendar years before settling in France are taxed only on the assets in the second category, meaning French property only, and that this lasts until 31 December of the fifth year after the year they established French tax residence. Service-public puts it identically: newcomers taxed abroad for the previous five years pay only on French-situated assets, for five years (see the newcomer note). A British executive relocating to Paris in 2026 who keeps a London flat therefore leaves that flat outside the IFI base until the end of 2031, while the Paris flat counts from day one. After the window closes, worldwide property enters the base.
Everything is photographed on 1 January. The statute says the conditions of liability are assessed on 1 January of each year, and the base is net value on that date. Buy on 2 January and the asset sleeps until next year’s photograph; sell on 2 January and this year’s bill stands. For British second-home owners this timing matters twice: it fixes the Euro-Sterling picture for your own budgeting, and it fixes which debts you may deduct, since only debts existing on 1 January count.
B. What counts, how it is valued and which debts come off: houses, SCI shares, mortgages and the 30 per cent relief
The base is defined by Article 965: the net value on 1 January of all buildings, land and property rights belonging to the liable persons and their minor children, plus shares in companies and bodies, French or foreign, up to the fraction of their value representing French or foreign property held directly or indirectly. In British terms this catches the holiday cottage itself, the Paris flat, bare ownership or life-interest rights (nue-propriété and usufruit) where you hold them, and crucially the shares of a société civile immobilière (SCI, the French family property company) apportioned to the underlying buildings. Holding through an SCI does not make the value disappear; it routes it through a fraction. British families who placed a French house in a trust should note that trusts have their own declaration machinery, explained in our guide to British family trusts facing French declaration, IFI and succession duties, and the same logic applies: France looks through the vehicle to the French bricks.
Valuation follows the death-duty rules. Article 973 provides that asset values are set under the rules for death duties, with one famous exception: a 30 per cent reduction on the true market value of the building occupied as the owner’s main home, one building only per jointly taxed household. The statute then grants the relief in these exact words: “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.” A British couple living full-time in their Provençal farmhouse therefore knocks nearly a third off its market value before the threshold test; a British non-resident whose French house is a second home gets no such reduction, which is often what pushes the holiday home over 1.3 million while an identical main home stays below. Listed securities held inside the same assurance-vie wrapper are measured by quoted prices, and unit-linked life contracts enter the base only for the fraction representing property assets.
Debts are where careful owners legally shrink the bill. Article 974 allows deduction of debts existing on 1 January, contracted and actually borne by the taxpayer, relating to taxable assets and proportionate to the taxable fraction: purchase costs, genuine repair and maintenance, improvement, construction, reconstruction and enlargement, property taxes other than occupier’s taxes, and acquisition costs of the taxable shares themselves. The official calculation guide restates the list with examples, including land tax (taxe foncière) and succession duties on the property as deductible, while occupier’s taxes such as the taxe d’habitation are not (see how the tax is calculated). For a British owner with a French mortgage, the outstanding capital on 1 January is the single biggest lever: capital-repayment loans are deductible year by year down to the remaining balance, while interest-only (in fine) loans follow a statutory amortisation. Company debts count only for the share relating to the buildings. Keep the 1 January loan statement every year; without proof the deduction dies.
Put numbers on it. Take a British resident in the UK owning a Luberon house worth 1,500,000 euros on 1 January, with 150,000 euros of mortgage capital outstanding: net taxable 1,350,000 euros. The official worked example on service-public uses exactly this band: gross IFI of 2,500 euros on the first slice plus 350 euros on the next, totalling 2,850 euros, then the smoothing relief below leaves 2,225 euros (see the worked example). Without the mortgage the same house would cost 3,600 euros. Valuation disputes of 100,000 euros either way move the bill by 500 to 700 euros a year at these bands, which is why the challenge machinery in Part II is worth real money. And remember that IFI sits beside the other French property bills, not instead of them: the 60 per cent second-home surcharge on the taxe d’habitation now hitting British owners, detailed in our report on the second-home surcharge after Brexit, and the rental-income regime for owners who let, covered in our guide to declaring UK rental income from France, all run in parallel.
II. How Do You Declare, Pay, Reduce and Challenge the IFI Bill After Brexit?
A. How British owners declare and pay: forms, deadlines, the 75 per cent cap and the British side of the Channel
Declaration rides with the income return. Article 982 requires liable persons to enter the gross and net taxable values on the annual return under Article 170, with administration-model annexes valuing each item, and spouses and PACS partners (outside the separated cases) must sign jointly. In practice this means the spring online return plus the 2042-IFI schedules, within the same deadlines as the income declaration (see declaring and paying IFI). British non-residents who file no French income return are not off the hook: the same official page directs them to file a standalone 2042-IFI with the 2042-IFI-COV identification form to their tax office. The trap for Britons is silence. France does not send a polite invitation to first-time IFI payers; the obligation to declare is yours, and the administration discovers newcomers through notaires’ filings, land-registry data and exchange of information. Failing to file when your net French property tops 1.3 million invites the taxation-in-default (taxation d’office) procedure, where, as the case law below shows, the administration must still prove you hold taxable assets above the threshold through a proper adversarial process.
The rate scale itself is progressive and starts below the threshold. Article 977 sets the bands: nothing up to 800,000 euros, 0.50 per cent from 800,001 to 1,300,000, 0.70 per cent to 2,570,000, 1 per cent to 5,000,000, 1.25 per cent to 10,000,000 and 1.50 per cent above. Being liable at 1.35 million therefore does not mean paying 0.7 per cent on everything; the lower slices are taxed at their own rates, which is why the example bill above is a few thousand euros rather than tens of thousands. A smoothing relief (décote) softens the cliff edge between 1,300,000 and 1,400,000 euros: the statute reduces the computed tax by “17 500 €-1,25 % P, où P est la valeur nette taxable du patrimoine.” At 1.35 million that relief is 625 euros, exactly as the official example shows.
Two genuine reducers survive for British payers. First, the cap (plafonnement). Article 979 reduces the IFI of a French tax resident where IFI plus French and foreign income taxes for the previous year exceed 75 per cent of worldwide net income, with only authorised categorical deficits deducted and exempt income and flat-rate-levy products added back. Note the cross-border generosity built into the verified text: foreign income taxes count in the comparison, so British-source income tax you paid in the UK on rents or pensions feeds the cap. The mechanism only helps French tax residents, not UK residents taxed solely on French property, which is one more reason the residence analysis in Part I comes first. Second, gifts. Article 978 allows a 75 per cent credit, up to 50,000 euros, for cash gifts and listed-share gifts to research bodies, recognised public-utility foundations and insertion enterprises among others. A 10,000 euro gift to an eligible foundation wipes 7,500 euros off the IFI, within the ceiling.
On the British side, organise your expectations honestly. The United Kingdom levies no equivalent annual wealth tax, so there is no British wealth-tax bill against which to set the French charge, and the UK government’s country guidance for Britons in France plus its foreign-income pages are the starting points for checking what must still be reported to HM Revenue and Customs (see Living in France and Tax on foreign income). French rental profits from the same house remain declarable and treaty-credited in the usual way, which our rental guide covers, and a future sale falls under the capital-gains machinery with its own exemption windows, explained for departing owners in our guide to selling the former French home after leaving for Britain. Treat IFI, income tax and capital-gains tax as three separate conversations with three separate challenge routes; winning one does not automatically fix the others.
B. How British owners challenge the bill: valuation proof, motivated replies and the Paris courts
Most IFI fights are valuation fights, and the courts have set the rules of that fight with unusual clarity. The starting definition comes from the Paris Court of Appeal, Pôle 5, Chamber 10, in its judgment of 30 September 2024, RG No. 22/19570 (read the decision). The court states: “Cette valeur peut être déterminée par comparaison avec les prix constatés pour des cessions de biens qui, sans être parfaitement identiques au bien en cause, lui sont intrinsèquement similaires, cette similitude portant sur l’état de fait et l’état de droit des biens.” Comparison is therefore lawful, but only with intrinsically similar properties in fact and in law: same neighbourhood dynamics, comparable size, condition, floor, light, layout, and comparable legal burdens such as tenancies, easements or planning constraints. The same judgment recalls the burden of proof under Article L. 17 of the Tax Procedure Book: where the declared price looks below true market value, the administration may reassess through the adversarial procedure, but it must prove the shortfall, and “le contribuable dispose de la faculté, pour contester le rehaussement notifié, de critiquer les éléments de comparaison retenus par l’administration fiscale.” For a British owner this is the practical playbook: attack comparables one by one, demand the sale dates, floor areas, condition reports and precise locations, and show dissimilarity in fact (a renovated top-floor flat is not your unrenovated first-floor one) or in law (a tenanted flat is not a vacant one).
The second weapon is procedural, and it comes from the highest court. In Cass. com., 24 June 2020, Appeal No. 18-10.477 (read the ruling), the Commercial Chamber quashed a Paris judgment that had blessed a thin administrative reply in a wealth-tax case. The court first restates the safeguard: “l’administration est toutefois tenue, en matière d’ISF, lorsqu’elle envisage de procéder à la taxation d’office des droits en cas d’absence de déclaration par le redevable, d’établir préalablement que celui-ci dispose de biens taxables dont la valeur nette est supérieure au seuil d’imposition, par la mise en oeuvre d’une procédure contradictoire comportant l’envoi d’une notification des bases d’imposition dans les formes et sous les garanties prévues par les articles L. 55 et L. 57 du livre des procédures fiscales.” Then comes the holding that every challenged owner should quote back: “alors que la réponse de l’administration aux observations par lesquelles le contribuable critique les termes de comparaison utilisés pour l’évaluation des biens taxables doit comporter les raisons qui justifient leur rejet, la cour d’appel a violé les textes susvisés.” A reply that merely asserts the administration need not give several comparables, without answering your detailed criticisms, violates the statute. Though decided under the former solidarity wealth tax (ISF), the reasoning governs IFI identically because Article 973 sends IFI valuation back to the same death-duty comparison method. Keep every exchange: proposal of rectification, your observations with notaire price data and expert valuations, and the administration’s reply. If the reply is boilerplate, the procedure itself is attackable.
The third decision sounds a necessary warning: courts do not refund on assertion alone. In TJ Paris, 19 January 2024, RG No. 22/08190 (read the judgment), the owner of two linked Paris flats used as a main home had filed IFI returns for 2019 to 2021, then claimed he had overvalued the flats and sought 8,137 euros back. The court rehearses the full framework, Articles 965, 973 and 761, the 30 per cent main-home reduction and the comparison method, then dismisses every claim: “DEBOUTE M. [S] [O] de ses demandes relatives à la restitution d’impôt”. The lesson for British claimants is blunt. A bare statement that the house is worth less, even with the main-home reduction correctly identified, recovers nothing without comparables, expert evidence and a coherent valuation date of 1 January. Commission an independent valuation from a French expert (expert immobilier) or notaire referencing dated comparable sales, file the administrative claim (réclamation) first, seek the departmental conciliation commission’s opinion where the administration offers it, and only then go to court. In Paris and the surrounding region, these disputes run through the regional public-finances directorate’s tax-litigation arm and the Paris judicial court, so Île-de-France owners should assemble the file locally: sale deeds from the neighbourhood, diagnostics, photographs of condition, tenancy schedules, and the 1 January loan statement.
Two final procedural points complete the picture. Late payment draws late interest at the Article 1727 rate, and Article L. 208 of the Procedure Book, quoted in the 2024 Paris appeal decision, provides that sums collected on an assessment later discharged are repaid with moratory interest at that same rate, through the collecting accountant rather than by a separate condemnation. And no court victory on IFI valuation rewrites your income-tax or capital-gains position by itself: each tax keeps its own assessment, its own claim and its own time limits, so calendar every deadline separately from the day the first proposal of rectification lands.
Conclusion
France’s IFI is not a Brexit punishment; it is an old French tax that now meets British owners without the European-law cushions of the past. If your French property, alone or with the rest of your household’s property wealth, is worth more than 1,300,000 euros net on 1 January, you are in the frame: on French assets only if your tax home is in Britain, on worldwide property if it is in France, softened for five years if you are a genuine newcomer. Value carefully under the death-duty comparison method, claim the 30 per cent reduction only where the French main home genuinely qualifies, deduct every provable 1 January debt, run the progressive scale with its smoothing relief, test the 75 per cent cap if you are French resident, and consider eligible gifts before the return goes in. And if the administration inflates your bricks, answer with better comparables and demand a reasoned reply, because the courts have said the proof is theirs and boilerplate is not an answer. Do the arithmetic early, file in spring, and keep the evidence from 1 January onwards.