I. Who pays the IFI and on what property

You live in London, New York or Geneva and you own a flat in Paris, a villa on the Côte d’Azur or shares in a family property company holding a house in Provence. Every spring, as the French income-tax campaign opens, the same question returns: do you owe France’s impôt sur la fortune immobilière (French real-estate wealth tax, known as the IFI), and if so, on which assets and for how much? For non-residents the answer is narrower than many foreign owners fear, but also easier to get wrong, because the tax catches indirect holdings, applies to net value measured on a single date, and follows its own filing circuit. This guide sets out, step by step, who is liable, how the base is computed, how to file from abroad, and how to challenge an assessment.

The IFI is an annual tax on real-estate wealth. It replaced the former solidarity tax on wealth and applies only to property assets, wherever the owner lives. Article 964 of the General Tax Code provides: 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 €. In plain English: the tax exists, and it bites once the value of the assets described in Article 965 exceeds 1,300,000 euros. That single threshold governs everything, but the assets counted toward it depend entirely on where you live for tax purposes.

A. Non-residents are taxed only on French property, direct or indirect

If your tax home (domicile fiscal, the place of your tax residence) is outside France, France can only tax the French part of your property wealth. Article 964 of the General Tax Code states that individuals without a French tax domicile are liable on French-situated property rights and on shares or units in companies and entities, in proportion to the fraction of their value representing those same French property assets. Your apartment in Berlin, your house in Florida and your shares in a German property fund are invisible to the IFI. Your Paris flat, your Provençal farmhouse and your stake in the French société civile immobilière (SCI, a non-trading property company) that owns them are fully visible.

The mirror rule matters just as much for foreign buyers planning to move to France. Individuals with a French tax domicile are in principle liable on worldwide property, but newcomers who have not been French tax residents during the five calendar years before settling in France are taxed, for five years, only on French-situated assets, under the same article. A buyer who relocates to Paris therefore keeps the non-resident-style base until 31 December of the fifth year following arrival. After that grace period, worldwide property enters the base, and foreign real estate must be valued and declared like French real estate.

Three traps catch foreign owners at this first stage. The first is the company wrapper. Holding French property through a foreign company does not remove it from the IFI. Article 965 of the General Tax Code includes shares in companies established in France or abroad, up to the fraction of their value representing property held directly or indirectly by the company, with a coefficient comparing the taxable property to total company assets. A Cypriot or Swiss holding company between you and the French villa changes nothing in principle: the administration looks through the chain to the French bricks. The second trap is the operating-company exception, which is narrow: shares in companies carrying on an industrial, commercial, craft, agricultural or professional activity are left out only where the taxpayer holds, directly or indirectly, alone or with the household, less than 10 percent of the capital and voting rights. A minority stake below that line in a genuine trading company escapes; a dedicated property vehicle never does. The third trap is the household. Married couples are taxed jointly except in the cases listed in Article 6(4), and the property of minor children under legal administration is added. Two spouses who each own 700,000 euros of French property are jointly above the threshold even though neither is individually.

International treaties add a final filter that must be checked before any filing. France’s tax treaties generally reserve to France the right to tax wealth consisting of French real estate, including through interposed companies, but each treaty has its own wording. The Cour de cassation applied exactly this analysis in a 2026 published ruling (Cour de cassation, Commercial Chamber, 6 May 2026, no. 24-22.185) concerning a Russian tax resident who held French property through a Cypriot company owning Swiss companies and stakes in two French property companies, and who sought repayment of wealth tax paid for 2015 and 2016. The Court held that the concept used by paragraph 2 of Article 22 of the France-Russia convention of 22 November 1996 takes the meaning given by domestic provisions, and it quoted the treaty rule: la fortune constituée par des actions, parts ou autres droits dans une société ou personne morale dont l’actif est principalement constitué, directement ou par l’interposition d’une ou plusieurs autres sociétés ou personnes morales, de biens immobiliers situés dans un Etat contractant ou de droits portant sur de tels biens est imposable dans cet Etat. In English: wealth consisting of shares or rights in a company whose assets consist principally, directly or through intermediate companies, of real estate situated in one contracting state may be taxed in that state. The claim for repayment was rejected. The lesson for any foreign owner is practical: before assuming a foreign holding structure shields the property, read the property article of the treaty between France and your state of residence, literally, as the Court does. Most treaties point back to France for French bricks, however many corporate layers sit in between. A treaty check belongs at the very start of the file, alongside the inventory of French assets, because it determines whether the rest of the computation even matters.

B. The 1.3 million euro net threshold, measured on 1 January for the whole household

The threshold is net, collective and frozen at a single date. The base is the net value of the taxable estate on 1 January of the tax year, after deducting qualifying debts, for the whole tax household. Owning 1.5 million euros of French property with 400,000 euros of deductible loans gives a net base of 1.1 million euros: no IFI. Owning 1.35 million euros outright gives a taxable base with only a small excess, softened by a statutory discount mechanism for bases between 1.3 and 1.4 million euros. Three consequences follow for foreign owners.

First, 1 January is everything. A sale completed in December removes the property from the following year’s base; a purchase signed in February enters it only the year after. Debts are judged at the same date: only debts existing on 1 January and actually borne by the taxpayer count, and later events, including a dispute that arises after that date, do not retroactively erase them. The Cour de cassation confirmed this timing rule in a 2024 ruling on deductible debts (Cour de cassation, Commercial Chamber, 4 April 2024, no. 22-19.335), holding: le seuil d’assujettissement à l’ISF porte sur la valeur nette des biens du redevable et s’apprécie au 1er janvier de chaque année d’imposition. In English: the liability threshold concerns the taxpayer’s net estate and is assessed on 1 January of each tax year. Although decided under the former wealth tax, the principle carries over identically to the IFI, whose base is likewise defined as net value on 1 January. For the foreign owner this means the year-end photograph decides the tax: January acquisitions financed by debt, December repayments, and gifts or transfers timed around the new year all change the picture, provided they are real, documented and effective before midnight on 31 December.

Second, the household aggregation can push a family over the line without any member feeling wealthy. A couple owning a 900,000 euro Paris flat and a 500,000 euro country house jointly holds 1.4 million euros of taxable property and owes the tax, even if each spouse thinks of their share separately. Property of minor children under the parents’ legal administration is added to the parents’ base. Conversely, adult children’s property is never aggregated, and each partner of an unmarried couple declares separately unless they are known cohabitants taxed under the specific cohabitation rule. Foreign families splitting ownership between spouses and children for succession reasons should therefore map the IFI household exactly as the statute defines it, not as the family perceives it: a gift of bare ownership to adult children genuinely removes value from the parents’ base, while a gift to minor children under administration does not.

Third, the threshold is a cliff with a cushion. Below 1.3 million euros net, nothing is due. From 1.3 million upward the progressive scale applies, but taxpayers whose net taxable estate is between 1.3 and 1.4 million euros receive a reduction equal to 17,500 euros minus 1.25 percent of the net taxable value, which smooths the entry into the tax. Just above the line the bill is therefore modest, sometimes a few hundred euros, and the real question is administrative: once over the line, the full declaration and valuation machinery applies. Owners hovering near the threshold should value carefully rather than rounding up out of caution, because an over-declared base above 1.3 million creates a filing obligation and a payment that a precise valuation might have avoided, while an under-declared base below the line invites reassessment. Precision at the boundary is worth more than anywhere else in the return.

II. Valuing, filing and defending the return

Once liability is established, the file becomes a valuation exercise with legal guardrails: every asset at its market value on 1 January, one targeted relief, deductible debts strictly listed, a progressive scale, and a declaration filed with the yearly income return. Each step has its own case law, and the administration’s room to reassess is fenced by procedure. Foreign owners who master these four links, valuation, debts, scale, filing, and who keep the evidence for each, pay the right amount and hold solid cards if the tax office disagrees.

A. Market value, the 30 percent relief and deductible debts

Valuation follows inheritance-tax rules: each property at its valeur vénale (open-market value) on 1 January. Article 973 of the General Tax Code sends the IFI to the valuation rules for death duties, and the courts apply a single definition. The Cour de cassation held in a 2019 published ruling (Cour de cassation, Commercial Chamber, 27 March 2019, no. 18-10.933): la valeur vénale d’un immeuble correspond au prix qui pourrait en être obtenu par le jeu de l’offre et de la demande sur un marché réel, compte tenu de la situation de fait et de droit dans laquelle l’immeuble se trouve lors du fait générateur de l’impôt. In English: the market value of a building is the price it could fetch through supply and demand on a real market, given the factual and legal situation of the property when the tax arises. That sentence is the whole valuation method in one line: real market, real condition, on 1 January. Legal characteristics count as much as physical ones, so a tenanted flat is worth less than the same flat vacant, a property burdened with a right of way or an inalienability clause is discounted, and co-ownership arrears or a voted special assessment for major works weigh on the price a buyer would actually pay.

In practice the administration values by comparison, using recent sales of similar properties in the same area, and the taxpayer answers with its own comparables. For a Paris apartment that means same arrondissement or adjacent streets, comparable size, floor, lift, condition and outlook, with sales close to 1 January. Notarial databases and published per-square-metre indices are useful starting points, but they are averages, not valuations: a ground-floor flat on a noisy boulevard is not worth the arrondissement median, and a top-floor flat with a balcony commands more. The 2019 ruling illustrates how concrete the court’s review is: the judges approved an appeal court that had examined the actual sale prospects of a co-owned main home held in joint ownership and concluded the undivided state did not depress its value, because neither spouse was likely to sell their share. The principle cuts both ways. Where a genuine discounting factor exists, an occupied property, a lease running for years, a dilapidated interior documented by photographs and quotes, it must be evidenced with comparables reflecting that same handicap. Where none exists, invoking a theoretical discount for joint ownership or family occupation fails. Foreign owners should therefore build a valuation file per property: three to five genuinely comparable sales with dates, surfaces and prices, the property’s specific handicaps and advantages, and, for high-value Paris assets, an independent appraisal dated near 1 January. That file is the shield in any later discussion with the tax office.

One relief dominates the computation for owners who live in their French property: the 30 percent reduction on the main home. Article 973 of the General Tax Code 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. In English: a 30 percent reduction applies to the real market value of the building where it is occupied as the owner’s main home. Three conditions are strict. The occupant must be the owner, so a flat lent free of charge to adult children or occupied by a tenant never qualifies. The occupation must be as a résidence principale (main home), meaning the effective, habitual dwelling, not a second home however intensively used. And only one property per jointly taxed household qualifies. For non-residents the relief is therefore rare but not impossible: a foreign owner whose effective main home is genuinely in France, typically a returning national or a newcomer in the five-year grace period, claims it on that dwelling. A holiday home in Provence used four months a year, however beloved, does not. Claiming the reduction on a second home is one of the most frequently reassessed items, and the administration tests effective occupation through energy bills, school enrolment, professional activity and time spent. If the main home is genuinely French, claim the relief and keep the proofs of occupation; if it is not, value the property at full market value and look for savings elsewhere.

Debts are the second lever, and the statute lists them exhaustively. Article 974 of the General Tax Code provides: 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. In English: deductible are debts existing on 1 January of the tax year, taken on by a person within the tax household and actually borne by that person. Eligible debts relate to acquisition costs, genuine repair and maintenance borne by the owner, improvement, construction, reconstruction or extension works, and certain taxes on the property. Consumer loans, income-tax arrears unrelated to the property and debts that are merely theoretical do not qualify. Two refinements matter for foreign buyers. First, debts contracted by an interposed company are handled under Article 973(II), which disregards debts the company took on to acquire a taxable asset from a person within the taxpayer’s circle: lending money to your own SCI so that it buys the villa back from you does not create deductible debt. Acquisition financing from a genuine third-party bank, by contrast, deducts normally, in proportion to the taxable fraction where the loan covers mixed assets. Second, timing and contestation decide deductibility, as the 2024 ruling recalled: only a debt that is uncontested on 1 January deducts, and a debt becomes uncertain, and therefore non-deductible, only from the day it is disputed following a reassessment procedure. A property-tax bill or a contractor’s invoice that you are actively disputing on 1 January cannot sit in the liabilities; the same debt, undisputed on that date, deducts even if you quarrel about it later. Keep the loan statements, the notarial financing record, the works invoices and the proof that each debt was still owed and still borne by you on New Year’s Day.

The scale itself is progressive and modest at the entry levels. Article 977 of the General Tax Code sets the rates: nothing up to 800,000 euros, 0.50 percent from 800,001 to 1,300,000 euros, 0.70 percent from 1,300,001 to 2,570,000 euros, 1 percent up to 5 million, 1.25 percent up to 10 million and 1.50 percent above. Because only the net base above 1.3 million triggers the tax, a 1.6 million euro net estate pays 0.50 percent on the 800,000 to 1.3 million slice plus 0.70 percent on the 300,000 euro excess, a bill of a few thousand euros, with the entry cushion for bases under 1.4 million softening the first step. Foreign owners sometimes confuse the threshold with the first bracket: the 0.50 percent slice between 800,000 and 1.3 million euros enters the computation once the threshold is crossed, which is why crossing the line by a small margin still produces a real, if modest, charge. A quick simulation before year-end, net base against the scale, tells you whether a December repayment, an additional deductible works bill or a precisely documented valuation keeps you below the line or at least in the cushioned entry band. General tax information of this kind does not replace advice on your personal situation, and cross-border financing interacts with the tax rules of your state of residence, but the arithmetic itself is public and worth running every December.

B. Filing from abroad and challenging an assessment

Declaration follows the income-tax return. Article 982 of the General Tax Code requires taxpayers to state the gross and net taxable values of the Article 965 assets on the yearly return provided for in Article 170, with schedules conforming to the administration’s model describing and valuing each component. In practice the IFI is therefore declared at the same time as yearly income, in the spring campaign, on the specific IFI schedules, and the official service-public guidance confirms the mechanics in English: the net taxable estate is valued on 1 January and reported with the income return, online filing being the default where the taxpayer’s main residence has internet access. Non-residents file through the non-resident tax department, and practical pitfalls abound: paper versus online access from abroad, exchange-rate conversion for loans denominated in foreign currency, and the need to attach the valuation schedules even when the base sits just above the threshold. A late, incomplete or missing return triggers interest, surcharges and, at the extreme, an ex officio assessment, so the calendar of the income campaign, which varies by filing channel and, for residents, by department, must be treated as the IFI calendar too. Diarise the opening of the campaign each April, file complete schedules with the valuation evidence behind them, and keep proof of filing and payment.

Where the administration disagrees, procedure protects the taxpayer at every stage, and recent case law shows the fences clearly. If you simply do not file, the tax office cannot invent a liability out of thin air. The Cour de cassation held in a 2020 ruling (Cour de cassation, Commercial Chamber, 24 June 2020, no. 18-10.477) that, while failure to file can lead to ex officio assessment of registration duties, in wealth-tax matters the administration must first establish, through an adversarial procedure with formal notice, that the taxpayer actually holds taxable assets above the threshold: d’établir préalablement que celui-ci dispose de biens taxables dont la valeur nette est supérieure au seuil d’imposition. In English: to establish beforehand that the taxpayer holds taxable assets whose net value exceeds the liability threshold. Silence therefore does not reverse the burden of proof; the administration must demonstrate, with comparables and documents served on the taxpayer, that the threshold is crossed before assessing of its own motion. For the foreign owner who receives an unexpected assessment, the first check is procedural: was there a prior formal notice, were the valuation comparables disclosed, and does the file show net assets above 1.3 million euros? If any link is missing, the assessment is vulnerable on procedure before valuation is even discussed.

The standard reassessment path runs through the proposition de rectification (proposed reassessment), dialogue, and then either acceptance, a formal réclamation (administrative claim) or litigation before the tax courts. Valuation disputes are won with comparables, not adjectives: answer each administration comparable with closer sales, commission a counter-appraisal for Paris properties where the spread is wide, and attack method errors such as comparing a tenanted flat with vacant sales or ignoring documented disrepair. Debt disputes turn on documents dated around 1 January: loan offers, bank statements showing the outstanding balance, works invoices and proof of actual payment by the taxpayer. Treaty disputes, for owners holding through foreign companies, turn on the literal wording of the applicable convention as the 2026 ruling demonstrates, convention by convention, article by article. And household disputes turn on civil status and administration of children’s property on 1 January. Throughout, respect the claim deadlines printed on each notice, reply to every interim letter within its time limit, and never let a reassessment become final by default while preparing the perfect argument. A timely, documented, procedurally exact challenge beats a brilliant late one, and the case law above shows that the courts enforce the administration’s own procedural duties strictly. For tailored analysis of a French property file with cross-border features, the firm’s Paris real-estate law practice handles valuation disputes, non-resident filings and reassessment litigation, and its overview of foreign buyers’ property matters in France sets out the broader purchase and holding framework within which the IFI sits.

Conclusion

France’s real-estate wealth tax reaches foreign owners, but only within precise boundaries: French-situated property, direct or traced through companies and treaty filters, net of qualifying debts, measured on 1 January for the whole household, and taxable only above 1.3 million euros. Below the line, no tax and no return to agonise over; just above it, a modest charge softened by the entry cushion; higher up, a progressive scale applied to a base that rewards careful valuation. The 30 percent main-home relief, deductible acquisition and works financing, and the five-year grace period for newcomers are the principal legal levers, each with strict conditions that must be documented rather than assumed. Filing rides with the yearly income return and demands complete valuation schedules, from abroad as from Paris. And where the tax office reassesses, procedure is the taxpayer’s first defence: the administration must prove the threshold is crossed before assessing of its own motion, must argue valuation with real comparables, and must respect the adversarial path the courts enforce. Map the French assets, check the treaty, photograph the debts on 1 January, value with evidence, file on time, and challenge in time: that sequence turns an intimidating foreign wealth tax into a manageable annual routine.