The letter is rarely labelled in English. It arrives as an avis d’impôt (a tax notice) or as a proposition de rectification (a proposed reassessment), and the heading that matters is IFI — impôt sur la fortune immobilière, France’s annual tax on net real-estate wealth. It is not council tax, not taxe foncière (the local property tax on the building), and not UK inheritance tax. It is a yearly charge on the market value of real-estate assets, after certain debts, once that net value on 1 January exceeds €1,300,000. British owners meet it in two typical situations: a UK-resident family with a valuable French house, château or set of SCI shares (société civile immobilière, a French civil real-estate company); or a household that has moved to France after Brexit and suddenly finds that a UK home, a French home and the shares in a family company are added together.

Brexit did not repeal IFI. The France–UK double tax treaty signed in London on 19 June 2008 is a convention on taxes on income and on capital gains. In Article 2 it lists, for the United Kingdom, income tax, corporation tax and capital gains tax, and for France income tax, corporation tax, the social contribution on corporation tax, payroll tax, CSG and CRDS. It does not list a wealth tax. A British passport, a Withdrawal Agreement residence card, or a visitor card does not, by itself, take a French house out of the IFI net. What changes the bill is tax residence, the five-year inbound rule for new French residents, the way shares and usufruct (usufruit, the right to use the property and take its fruits) are valued, and the debts the statute actually allows you to deduct. This note is for the British owner or resident who has to decide whether to file form 2042-IFI, who has received a bill that looks too high, or who has been told that a family loan or an SCI current account cannot be deducted. Buying the house, and incorporating a trading company, sit outside this note; the person, the French tax home, the declaration and the challenge do not.

I. Do I have to pay French IFI after Brexit as a British owner?

A. Who is taxed: French tax residents, new arrivals from the UK, and owners who still live in Britain

French law draws a hard line between people who have their tax home in France and people who do not. Article 964 of the code général des impôts (CGI, the French tax code) creates the tax in these terms: « Il est institué un impôt annuel sur les actifs immobiliers désigné sous le nom d’impôt sur la fortune immobilière. Sont soumises à cet impôt, lorsque la valeur de leurs actifs mentionnés à l’article 965 est supérieure à 1 300 000 € : 1° 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. » In plain English: if you are a French tax resident and the net real-estate assets listed in article 965 exceed €1,300,000 on 1 January, France taxes those assets wherever they sit — including a house in Devon, a London flat, and a French farmhouse.

The same article 964 of the CGI then carves out people who do not have their French tax home in France: « 2° 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. » A British owner who remains tax-resident in the UK is therefore taxed only on French-situs real estate and on the real-estate fraction of company shares, not on the UK home. The French tax administration says the same thing on its non-resident pages: a person living outside France is taxable on IFI only in respect of real-estate assets and rights located in France and on shares to the extent they represent French property, if the household’s net taxable real-estate wealth exceeds €1.3 million. That is the rule that catches a second-home owner in Dordogne, a Paris apartment held through an SCI, or a family château whose shares have been split among siblings.

Whether you are a French tax resident is not a matter of taste, nor of the sticker in your passport. Article 4 B of the CGI states: « 1. Sont considérées comme ayant leur domicile fiscal en France au sens de l’article 4 A : a. Les personnes qui ont en France leur foyer ou le lieu de leur séjour principal ; b. Celles qui exercent en France une activité professionnelle, salariée ou non, à moins qu’elles ne justifient que cette activité y est exercée à titre accessoire ; » and, under c, those who have in France « le centre de leurs intérêts économiques ». One criterion is enough. The same article then bows to treaties: « Les personnes qui satisfont à l’un au moins des critères fixés aux a à c du présent 1 ne peuvent toutefois pas être considérées comme ayant leur domicile fiscal en France lorsque, par application des conventions internationales relatives aux doubles impositions, elles ne sont pas regardées comme résidentes de France. » The 2008 treaty can therefore decide that you are a UK resident for income tax even if French domestic law would have treated you as French. That treaty fight is a residence fight. It does not, by itself, switch IFI off, because IFI is not one of the taxes listed in Article 2 of the convention.

Article 2 of that 2008 convention is built as a list of taxes on income and on capital gains. The United Kingdom side names income tax, corporation tax and capital gains tax. The French side names income tax, corporation tax, the social contribution on corporation tax, payroll tax, CSG and CRDS. There is no French wealth tax in that list, and no UK equivalent. A British owner who writes to HMRC or to the service des impôts (the local tax office) saying “the treaty prevents double taxation of my house” is answering the wrong question. The UK does not levy a yearly wealth tax on the French cottage. France does. There is, in the ordinary case, nothing for the treaty credit to bite on.

New arrivals get a temporary territorial limit, and it is one of the few Brexit-era moving points that still works in the taxpayer’s favour. Article 964 of the CGI goes on: « Toutefois, 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°. » If you transfer your tax home to France after five full calendar years of being tax-resident abroad, France taxes you, for IFI, only on French-situs real estate and on the French-property fraction of shares, until 31 December of the fifth year after the year in which the French tax home was established. A British couple who leave London in 2026, become French tax residents that year, and still own a UK house, do not add the UK house to the IFI base during that inbound window. They do add the French house, the French SCI shares, and any other French real-estate rights. Service-public.fr, checked on 6 March 2026, repeats the same inbound rule for readers who have just transferred their tax home to France.

The household is wider than many British couples expect. Article 964 provides that, except in the cases in article 6(4)(a) and (b) of the CGI, married couples are taxed jointly, as are partners bound by a pacte civil de solidarité (PACS, the French civil partnership). Service-public.fr adds that the IFI household also includes a couple living together without marriage or PACS, and the real-estate of minor children whose legal administration you hold. A British husband who has moved to France while his wife remains in Kent can therefore find that the administration tries to join assets, or that a PACS signed in France pulls both estates into one IFI return. That is a residence-and-household question, not a nationality question; it is the same issue we have already mapped for British couples split between France and the UK who must prove tax residence after Brexit.

Non-residents have a further, practical Brexit sting. Article 983 of the CGI provides: « Les personnes possédant des actifs mentionnés à l’article 965 situés en France sans y avoir leur domicile fiscal ainsi que les personnes mentionnées au 2 de l’article 4 B peuvent être invitées par le service des impôts à désigner un représentant en France dans les conditions prévues à l’article 164 D . » The exemption from that invitation is written for residents of another EU Member State or of an EEA State that has signed both an administrative-assistance convention and a mutual-recovery convention with France. The United Kingdom is no longer in that list. A UK-resident owner of a French house can therefore be asked to appoint a représentant fiscal (a fiscal representative in France). That is not a tax in itself; it is a channel of notification. Ignoring the invitation is how deadlines are missed.

In Paris and the rest of Île-de-France the file does not travel to a “British desk”. A UK-resident owner files with the Direction des Impôts des Non-Résidents (DINR, the tax office for non-residents), SIPNR, 10 rue du Centre, TSA 10010, 93465 Noisy-le-Grand CEDEX, which is the address given by impots.gouv.fr for paper IFI returns of non-residents. A British resident who lives in Paris files with the service des impôts des particuliers for the arrondissement of the tax home, in the same spring campaign as the income-tax return. Reassessments of IFI in the Paris region are often handled by the regional public-finance directorate’s judicial-tax unit; when the dispute later reaches a court, the Paris cases visible in the open case-law are heard by the tribunal judiciaire de Paris, 9th chamber. The pieces to have on the table before you write are the 1 January valuation, the loan statements, the SCI accounts, and the residence evidence — not a print-out of the treaty.

B. What goes into the IFI base: the French house, SCI shares, usufruct, trusts and the 30% main-home abatement

The base is a net value on 1 January, not a running average and not the price you paid in 2004. Article 965 of the CGI opens: « L’assiette de l’impôt sur la fortune immobilière est constituée par la valeur nette au 1er janvier de l’année : 1° 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 ; 2° 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. » Direct ownership of a house, a flat, land, a building plot, a property under construction, an usufruct or a right of habitation sits in 1°. Shares sit in 2°, whether the company is French or foreign, but only for the fraction that represents real estate.

That fraction is why a holiday-home SCI does not take the house out of IFI. Article 965 tells you to apply to the value of the shares, determined under article 973, a coefficient equal to the ratio of the market value of the taxable real-estate assets (and of shares representing those assets) to the market value of all the company’s assets. A British family that holds a French holiday home through an SCI is therefore still looking at IFI on the real-estate fraction of those shares. Article 966 of the CGI stops the usual “trading company” escape: « I.-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. » A company whose activity is managing its own property portfolio is not, for this purpose, carrying on a commercial activity. A family SCI that owns the cottage and collects a few weeks of rent is in the IFI base. A company that actually runs an industrial, commercial, craft, agricultural or professional business can keep its operating premises out, under the professional-asset exemption in article 975, but that exemption is about the activity, not about the passport of the shareholder.

Usufruct is the other trap in Franco-British families. After a death, a British widow is often advised to take a French usufruct of the family home while the children take the nue-propriété (bare ownership). Article 968 of the CGI starts from a severe default: « 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 usufructuary is taxed on the full freehold value, not on a slice. The article then allows a split according to the age scale in article 669 only in listed cases — including an usufruct that arises under the surviving-spouse rights in the Civil Code, provided the right has not been sold or given away. A homemade split, or a reserved usufruct on a sale to the children that does not fit those cases, can leave the parent taxed on 100% while the children are also in the picture. That is a valuation fight, and it is not solved by an English will.

UK trusts are not invisible. Article 970 of the CGI provides: « Les actifs mentionnés à l’article 965 placés dans un trust défini à l’article 792-0 bis sont compris, pour leur valeur vénale nette au 1er janvier de l’année d’imposition, selon le cas, dans le patrimoine du constituant ou dans celui du bénéficiaire qui est réputé être un constituant en application du II du même article 792-0 bis. » Real estate, or shares representing real estate, sitting in a UK trust can be pulled into the settlor’s IFI base, or into the base of a beneficiary who is treated as a settlor. The limited exception for irrevocable trusts whose exclusive beneficiaries are bodies of the kind listed in articles 795 and 795-0 A is not a family-trust escape. A British resident in France who still has a UK family trust holding a French farm, or shares in a company that holds one, needs the trust mapped for IFI as well as for the separate trust-reporting rules we have already set out for British residents who must declare a UK trust in France.

The main home, if you are a French tax resident occupying it as your résidence principale (principal residence), is not exempt. It is abated. Article 973 of the CGI states: « Par dérogation au deuxième alinéa de l’article 761 , 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. En cas d’imposition commune, un seul immeuble est susceptible de bénéficier de l’abattement précité. » Service-public.fr, verified on 6 March 2026, repeats that the 30% abatement applies to the market value on 1 January 2026. A British retiree who has made the French house the family home can therefore declare 70% of that house. A UK-resident owner of a second home cannot. A couple cannot abate two homes. The abatement is also not a licence to invent a low value: article 973 I says that IFI assets are valued according to the rules for inheritance-tax valuations, and service-public.fr describes valeur vénale réelle as the price at which the property could have been sold on the market on 1 January.

That 30% figure is where many bills go wrong in both directions. Owners forget it and overpay. The administration denies it because the occupant is a company, a child, or a tenant, or because the household already claimed it on another building. The open case-law on IFI is still thinner than the old ISF case-law, but first-instance courts are now applying articles 965 and 973 to live files. The tribunal judiciaire de Compiègne, in its judgment of 2 September 2025, RG n° 24/00911, had before it a proposed IFI reassessment for 2020 and 2021 on SCI shares. The administration relied on article 973 II, which the court recorded as the « clause anti-abus » excluding certain debts from the valuation of shares. The court quoted article 965 in full on the net value at 1 January and on the real-estate fraction of shares, then applied the debt rules. That is the litigation posture a British family with an SCI should expect: not a debate about nationality, but a debate about 1 January value, the coefficient, and which debts still exist.

II. How do I calculate IFI, file the return and challenge a bill that looks wrong?

A. How the tax is calculated, which debts you can deduct, and which 2042-IFI return you actually file

Once the net taxable value on 1 January is above €1,300,000, the scale does not start at €1,300,000. It starts at €800,000. Article 977 of the CGI fixes the tariff: the slice not exceeding €800,000 is taxed at 0%; the slice above €800,000 and up to €1,300,000 at 0.50%; above €1,300,000 and up to €2,570,000 at 0.70%; above €2,570,000 and up to €5,000,000 at 1%; above €5,000,000 and up to €10,000,000 at 1.25%; above €10,000,000 at 1.50%. Service-public.fr’s 2026 table matches that scale and adds the warning: you are subject to IFI when the net taxable value of non-professional real-estate wealth exceeds €1,300,000 on 1 January 2026, but in that case the tax is computed from €800,000. A household at €1,290,000 pays nothing. A household at €1,310,000 pays on the slice from €800,000.

There is a smoothing rule at the threshold. Article 977 of the CGI also provides: « Pour les redevables dont le patrimoine imposable a une valeur nette taxable égale ou supérieure à 1 300 000 € et inférieure à 1 400 000 €, le montant de l’impôt calculé selon le tarif prévu au tableau du 1 est réduit d’une somme égale à 17 500 €-1,25 % P, où P est la valeur nette taxable du patrimoine. » Service-public.fr works an example at €1,350,000 on 1 January 2026: gross IFI €2,850, abatement €625, tax due €2,225. That is not a British-only concession. It is the statutory décote, and it is worth checking on any notice that has just crossed €1.3 million after a French renovation or a jump in local prices.

Debts are where British files are most often rebuilt by the administration. Article 974 of the CGI allows deduction only of debts that exist on 1 January, contracted by a person mentioned in article 965-1°, actually borne by that person, and related to taxable assets: « I.-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 et, le cas échéant, à proportion de la fraction de leur valeur imposable : 1° Afférentes à des dépenses d’acquisition de biens ou droits immobiliers ; » then repair and maintenance costs, improvement, construction, reconstruction or enlargement, taxes that fall on the owner rather than the occupier, and the cost of acquiring taxable shares in proportion to the real-estate fraction. Taxe foncière can therefore come in; a disputed taxe foncière bill is a different tax, but the amount due as owner can be an IFI debt. Occupier’s taxes, including the remaining taxe d’habitation on a second home, are not IFI debts. Income tax on rental income is not an IFI debt.

Bullet loans and loans with no term are written down by formula. Article 974 II provides that a loan whose capital is repayable at the end of the contract is deductible each year only for the original capital reduced by that capital multiplied by the number of years already elapsed and divided by the total term. A loan with no repayment date for the capital is written down by one-twentieth for each year since the funds were advanced. A British interest-only mortgage that looked fully deductible on day one is therefore not fully deductible in year ten. Family loans are narrower still. Article 974 III shuts out loans contracted, directly or through companies, from the taxpayer, the spouse, the PACS partner or the cohabitee, or from their minor children; loans from other ascendants, descendants, brothers or sisters are shut out unless the taxpayer proves that the terms are normal, including actual repayments on time. Loans from a company the family controls are shut out on the same “normal terms” test. Article 974 IV then clips large files: where the market value of the taxable assets exceeds €5 million and deductible debts exceed 60% of that value, the excess debts are only half deductible, unless the taxpayer shows that they were not contracted with a mainly fiscal objective.

Inside an SCI, article 973 II is the companion anti-avoidance rule. It disregards, when valuing the shares, debts contracted by the company to acquire a taxable asset for a person who controls the company, and debts contracted from such a person, in the cases it lists. That was the provision at stake in Compiègne. The tribunal recorded that the taxpayers held all the shares in SCI THINIPRO, that the company had acquired property belonging to them, and that the financing included shareholders’ current-account contributions rather than a bank loan. The administration treated the debt as caught. The court looked at the wider estate-planning operation, including a later donation-partage (a notarised gift-and-division) of 1 June 2022, the husband’s health, and the couple’s stated wish, as former farmers, to rebalance the spouses’ estates and keep some liquidity for retirement. The tribunal judiciaire de Compiègne, in the same judgment of 2 September 2025, RG n° 24/00911, then held: « Comparé à la charge fiscale économisée au titre de l’IFI, le coût de ces opérations et les avantages recherchés permettent de considérer que le redevable a apporté la démonstration que l’objectif principalement recherché n’était pas principalement fiscal au sens des dispositions citées ci-dessus. » The court granted extra relief of €5,965 of IFI for 2020 and €5,918 for 2021, plus late-payment interest. The lesson for a British SCI is not that current-account funding always survives. It is that the statute asks for a mainly non-fiscal purpose, evidenced in time, and that a first-instance court will weigh the notarial file against the tax saved.

French tax residents can also cap the bill against income. Article 979 of the CGI reduces IFI, for a person with a French tax home, by the excess of (IFI plus income taxes due in France and abroad on the previous year’s income) over 75% of world income of the previous year, with the additions the article then makes. The Conseil d’État has treated that cap as a genuine legislative mechanism, not as a cash-flow favour. In its decision of 31 March 2021, n° 440576, it quoted the first sentence of article 979 I word for word: « L’impôt sur la fortune immobilière du redevable ayant son domicile fiscal en France est réduit de la différence entre, d’une part, le total de cet impôt et des impôts dus en France et à l’étranger au titre des revenus et produits de l’année précédente, calculés avant imputation des seuls crédits d’impôt représentatifs d’une imposition acquittée à l’étranger et des retenues non libératoires et, d’autre part, 75 % du total des revenus mondiaux nets de frais professionnels de l’année précédente, après déduction des seuls déficits catégoriels dont l’imputation est autorisée par l’article 156, ainsi que des revenus exonérés d’impôt sur le revenu et des produits soumis à un prélèvement libératoire réalisés au cours de la même année en France ou hors de France (…) ». The Court then held that the legislator intended the charge for a given year to be payable out of the previous year’s income without overburdening ability to pay, and it dismissed an attempt to rewrite the 2019 cap around withholding-tax cash flows. A British resident in France with a large house and modest pension income may therefore have a cap claim. A UK-resident second-home owner does not: article 979 is written for the person « ayant son domicile fiscal en France ».

The return is attached to the income-tax return. Article 982 of the CGI provides: « 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 . 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 is form 2042 plus form 2042-IFI and its annexes. Service-public.fr, on the 2026 declaration page, says you declare IFI with the income of the previous year — so in 2026, with 2025 income — in the same spring campaign as the income-tax return, online if the main home has internet access. The 2026 campaign for 2025 income is closed; the 2027 campaign for 2026 income is announced as starting in April 2027. Spouses and PACS partners must both sign. Unmarried cohabitees put both estates on one of the two returns. Non-residents who also file a French income-tax return send the paper file, if they are still on paper, to the DINR in Noisy-le-Grand. Non-residents with no French income-tax return file 2042-IFI plus 2042-IFI-COV. Payment is on the later tax notice: online is mandatory above €300.

Late filing is expensive. Service-public.fr states that a delay after a formal notice (mise en demeure) attracts a 10% surcharge if you file within 30 days of that notice, and 40% beyond that; the 10% is raised to 40% where the filing follows the disclosure of undeclared foreign assets; late-payment interest runs at 0.20% a month from 1 July of the year the return should have been filed. An inaccurate value attracts the same monthly interest, with a 10% valuation margin if good faith is not challenged, and with a written, on-return explanation protecting you where you have said why a particular asset is omitted or valued as it is. Deliberate omission is another statute. None of those surcharges is a substitute for a claim on the merits. They are why a British owner who has just crossed €1.3 million should file a conservative 2042-IFI on time, then correct, rather than wait for a better valuation from a UK surveyor who has never seen a French compromis.

B. How to challenge an IFI notice or a reassessment, and which court hears the case

A challenge does not start in court. It starts with a réclamation contentieuse (a formal tax claim) to the administration that issued the notice. If the administration has opened an audit, the first document is usually the proposition de rectification. Article L. 57 of the livre des procédures fiscales (LPF, the tax-procedure code) requires: « L’administration adresse au contribuable une proposition de rectification qui doit être motivée de manière à lui permettre de formuler ses observations ou de faire connaître son acceptation. » You have a short period in which to reply; on request received before that period expires, article L. 11 LPF can add thirty days. A British owner who answers with a narrative letter and no 1 January comparables, no loan table and no SCI balance sheet has not used the right. The reply is the place to put the inbound five-year rule, the 30% main-home abatement, the article 974 write-down of an interest-only loan, and the evidence that a family loan was actually repaid.

If the tax is already on a notice, the claim deadline is the end of the second following year. Article R.* 196-1 of the LPF, in force, states: « 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 ; c) De la réalisation de l’événement qui motive la réclamation. » IFI is not a local direct tax. A notice notified in 2026 is, in the ordinary a) case, claimable until 31 December 2028. Missing that date is fatal to the ordinary claim, whatever the treaty says. Paying the tax does not kill the claim; it can even be the b) starting point where there was no assessment roll. A later court decision is not, under the last sentence of the same article, an “event” of the c) kind.

The claim is written, signed, and sent to the tax office named on the notice, with the notice, the computations, and the evidence. For a UK-resident owner that office is the DINR in Noisy-le-Grand. For a Paris resident it is the Paris service des impôts des particuliers that issued the avis. The claim can ask for discharge or reduction. It can also ask for a stay of payment, under the separate LPF rules on sursis de paiement, if you are not in a position to pay a six-figure IFI while the valuation is fought. Silence for six months is, in the usual LPF pattern, an implied rejection that opens the court. An express rejection letter does the same, and it starts the two-month period in which you must bring the case.

IFI is not heard by the administrative court that hears a préfecture visa refusal. Live IFI litigation is before the tribunal judiciaire (the ordinary judicial court). The Compiègne judgment of 2 September 2025 is a first-instance IFI judgment of that court, sitting in tax proceedings, after a proposed reassessment and a claim. Paris files of the same kind appear in the 9th chamber of the tribunal judiciaire de Paris. You do not write to the tribunal administratif de Paris about an IFI notice. You file, through an avocat, at the judicial court with territorial jurisdiction, within the period that runs from the rejection of the claim. The court can reduce the tax, as Compiègne did, and it can deal with costs; it does not award damages for a wrong assessment. Article L. 207 LPF, which the Compiègne court quoted, confines the successful claimant to moratory interest under article L. 208, not to damages.

What wins, on the files that are actually being tried, is arithmetic tied to a statutory head of claim. Undervaluation of a Dordogne farmhouse is a market-value argument under article 973 I, to be evidenced with local comparables, the Patrim service, and the defects a French notaire would disclose, not with a UK estate-agent letter headed “for probate”. A refused 30% abatement is a principal-residence argument: who lived in the house on 1 January, on whose return, and whether another property already took the abatement. A refused inbound exemption is a five-calendar-year residence argument, documented with UK tax returns, P60s, and the date the French tax home was established. A refused debt is an article 974 argument: existence on 1 January, link to a taxable asset, write-down of an interest-only loan, and proof of actual repayment of a family loan. An SCI share argument is an article 965 coefficient plus article 973 II. A trust argument is article 970. Mixing those heads in one emotional letter is how a good point is lost.

Brexit adds no extra time. It does add extra documents. A UK-resident owner should expect the DINR to ask for a French fiscal representative under article 983, for a valuation that a French office can read, and for evidence that the household’s other French assets have been counted. A new French resident should expect the office to test the five-year inbound rule against the UK house, then, once the fifth 31 December has passed, to add that UK house to the worldwide IFI base. A British owner who has already been through a second-home taxe d’habitation challenge will recognise the pattern: the local tax and IFI are different statutes, but both are 1 January photographs, both are claimed in writing, and both are lost by waiting for a telephone call that never comes.

If the notice is right on the law and wrong only on the figures, a corrected 2042-IFI or a claim limited to quantum is faster than a full-scale attack on liability. If the notice is wrong on residence, the inbound rule, or the inclusion of a UK asset during the five-year window, the claim should say so in the first paragraph, with dates. If the administration has already issued a motivated proposition de rectification, the observations under article L. 57 are the first pleading, not an informal email to the inspector. In Île-de-France, keep the DINR or Paris SIP letter, the AR (recorded-delivery) slip, and a running table of 1 January values. Those are the papers the 9th chamber will want if the claim is rejected.

Conclusion

IFI is a French annual tax on net real-estate wealth above €1,300,000 on 1 January. Brexit did not delete it, and the 2008 France–UK treaty does not list it among the taxes it covers. A British owner who remains tax-resident in the UK is taxed only on French real estate and on the French-property fraction of shares. A British owner who has become a French tax resident is taxed on worldwide real-estate assets, subject to the five-year inbound limit that keeps foreign property out until 31 December of the fifth year after the French tax home was established. Shares in a family SCI that merely holds the house stay in the base; usufruct is taxed at full value unless a statutory split applies; a UK trust can be looked through to the settlor. The 30% abatement is for one principal residence occupied by the owner. Debts must exist on 1 January, sit on a taxable asset, and survive the write-down and family-loan rules. The return is form 2042-IFI, in the spring, with the income-tax return or, for a non-resident without French income, with 2042-IFI-COV to the DINR. A wrong bill is challenged by a written claim, usually by 31 December of the second year after the notice, then before the tribunal judiciaire, not the administrative court. The next useful step is to reconstruct the 1 January picture — residence, assets, debts, shares — before the filing date or before the claim deadline, rather than after a surcharge has already been posted.

Need a quick opinion on your case

Talk the IFI notice, the 2042-IFI figures, the SCI accounts and the residence position through with an avocat before you file, before you pay, or before the claim deadline expires. Our firm offers a telephone consultation within 48 hours with an avocat of the firm. Call +33 6 46 60 58 22 (Maître Reda Kohen), or reach us through our contact page. We assist British owners and residents in Paris and across the Paris region as well as throughout France.