You live in Manchester, Leeds or London, and you still own the two-bedroom flat in Lyon, Nantes or the Paris suburbs that you bought before Brexit. Rather than sell it, you let it unfurnished on a three-year residential lease while you remain resident in the United Kingdom for tax purposes. Every spring, the same questions come back: does France really have the right to tax that rent when you already pay tax in Britain, which French tax return do you file as a non-resident, is the simplified micro-foncier regime really simpler for you, and what can you do when the French bill looks wrong? This article answers those four questions in order. It explains first where France takes its taxing right and how the net rental profit is calculated under the revenus fonciers rules, then the two surcharges that hit non-residents specifically — the minimum 20 and 30 per cent rates with the worldwide average-rate option, and the 7.5 per cent solidarity levy — and finally how the France–United Kingdom double tax treaty of 19 June 2008 shares the tax between the two countries and how you challenge an excessive French assessment. All the key French terms are explained as they appear: revenus fonciers means rental income from unfurnished lettings, micro-foncier is the simplified flat-rate regime, régime réel is the actual-expenses regime, prélèvement de solidarité is the solidarity levy on property income, and taux moyen is the average-rate option. The law is stated as verified on 6 October 2026, with the official texts and recent court decisions quoted in support.

I. France taxes your French rents first: the taxing right and the calculation of the net profit

A. Why France taxes the rent even though you live in Britain, and which return you file

The starting point is blunt and surprises many British owners: living in the United Kingdom does not shield your French rental income from French tax. Article 4 A of the French General Tax Code (code général des impôts) provides that “Celles dont le domicile fiscal est situé hors de France sont passibles de cet impôt en raison de leurs seuls revenus de source française”, meaning persons whose tax domicile is outside France are liable to French income tax on their French-source income only — but fully liable on that income. The leading French commentary and the official Article 4 A of the General Tax Code confirm the split: worldwide taxation for French residents, territorial taxation for everyone else. Your tax domicile itself is decided by Article 4 B of the General Tax Code, which treats as domiciled in France persons whose home, principal place of residence or main professional activity is in France. If your home, family life and work are all in Britain and you merely own a flat in France, you are non-resident, and France taxes only your French-source income — but your French rents are the textbook example of such income.

That is because Article 164 B of the General Tax Code lists, among income treated as of French source, “Les revenus d’immeubles sis en France”, income from buildings situated in France. The Conseil d’État confirmed the breadth of that phrase in a decision of 13 March 2026 concerning non-resident landlords: “Constituent des revenus d’immeubles au sens de ces dispositions les loyers issus d’immeubles situés en France, quelle que soit la catégorie d’imposition dont ils relèvent”, meaning any rent from a building in France counts, whatever income category it falls into for income tax purposes (CE, 13 March 2026, No 503496). The France–United Kingdom treaty of 19 June 2008 points the same way: as the French tax administration’s official commentary on the treaty (BOI-INT-CVB-GBR, France–UK treaty) recalls, income from immovable property situated in one of the two States may be taxed in that State, so France as the situs State taxes the rent and the United Kingdom as your residence State gives relief against double taxation, normally by credit. You therefore declare the rent in France first, pay the French tax computed under French rules, then report the same rent on your British Self Assessment return and claim foreign tax credit relief for the French tax attributable to it, within the limits set by HM Revenue & Customs and by Article 24 of the treaty.

In practice, the French filing is straightforward once you know the forms. The tax administration’s official guidance for non-residents letting an unfurnished property states: “Il vous suffit d’indiquer sur la déclaration n° 2042 (case 4BE) le montant brut des revenus fonciers perçus” under the micro-foncier regime, with no annexed return, while under the actual-expenses regime you complete return No 2044 (or the special 2044-SPE for particular schemes) and carry the resulting profit or deficit to return No 2042, and “Si vous optez pour le taux moyen d’imposition, vous devez déclarer vos revenus mondiaux (revenus de sources française et étrangère) afin de permettre la détermination de ce taux” (impots.gouv.fr, non-resident unfurnished letting guidance). The general filing duty itself comes from Article 170 of the General Tax Code, which requires every person liable to income tax to file a detailed return of income, and expressly adds that where the taxpayer is not taxable on all of his income, the return is limited to the income subject to French tax — exactly your situation. File online through your impots.gouv.fr personal account where possible, keep the lease, the rent receipts, the managing agent’s statements and proof of every expense, and never assume that because you pay tax in Britain you can skip the French return: the French assessment is computed on the French return, and a missing or late return triggers penalties and blocks later challenges.

Two distinctions matter before any calculation. First, this article covers unfurnished lettings taxed as revenus fonciers only; furnished lettings fall under industrial and commercial profits with different registration, accounting and allowance rules, and are examined in our companion guide to furnished letting by British owners. Second, the mirror situation — living in France and letting out a house you kept in England — follows different declaration forms and the other direction of the treaty credit, covered in our guide to British landlords in France with UK rental income. Mixing the two directions is the most common source of error we see in British files.

B. Micro-foncier or actual expenses: how your taxable profit is really calculated

Once France’s taxing right is established, everything turns on one definition. Article 14 of the General Tax Code brings into the revenus fonciers category, where they are not part of a business profit, the income from built property such as houses and flats, and the income from unbuilt property of every kind. Your unfurnished flat therefore produces revenus fonciers by nature, and the only question is how the net amount is measured. Article 28 of the General Tax Code states the formula in one sentence: “Le revenu net foncier est égal à la différence entre le montant du revenu brut et le total des charges de la propriété”, the net rental profit equals gross receipts minus total property charges. The whole choice between the two regimes is a choice about how that subtraction is made: a fixed 30 per cent allowance with almost no paperwork, or the deduction of your real charges with full proof.

The simplified route is the micro-foncier regime in Article 32 of the General Tax Code: “lorsque le montant du revenu brut annuel défini aux articles 29 et 30 n’excède pas 15 000 €, le revenu imposable correspondant est fixé à une somme égale au montant de ce revenu brut diminué d’un abattement de 30 %”, meaning that where the annual gross rental receipts do not exceed 15,000 euros, the taxable amount is the gross minus a 30 per cent flat allowance. For a British owner collecting, say, 12,000 euros of annual rent on a provincial studio, the taxable base is 8,400 euros, declared directly on return No 2042 without annexe 2044, exactly as the official non-resident guidance quoted above confirms. The regime applies to all the tax household’s rental income together, it is lost for the year if any member of the household owns property under a special deduction or amortisation scheme, a historic monument, or bare ownership let property, and it cannot be combined with the deduction of real charges: you cannot take the 30 per cent and then add the insurance or the managing agent’s fees on top. For many British owners with a single modest flat, no mortgage interest and low charges, micro-foncier wins on simplicity and often on amount; for owners with heavy deductible charges, it loses money every year it is kept by default.

The alternative is the régime réel, the actual-expenses regime, where you deduct the charges listed in Article 31 of the General Tax Code, whose first paragraph for urban property covers repair and maintenance expenditure actually borne by the owner, insurance premiums, sums borne for the tenant’s account that could not be recovered by 31 December of the year the tenant left, co-ownership provisions under Article 14-1 of the Law of 10 July 1965, and, further down the same article, management costs, certain taxes and loan interest. Three practical points decide most British files. First, only charges you actually paid and can prove are deductible, so keep every invoice, bank transfer and agent statement; a British bank statement showing a sterling transfer to a French artisan is proof, but only if the invoice behind it describes work on the let flat. Second, the line between deductible repair and non-deductible improvement or reconstruction is policed strictly: repainting, boiler servicing, replacing a worn carpet or mending the existing bathroom are normally deductible, while adding an extension, converting the attic into a second bedroom or rebuilding the flat to a higher standard is generally treated as improvement or construction and excluded. Third, loan interest on the mortgage used to buy or repair the let flat is deductible, but capital repayments are not, and the rule is simple: interest yes, capital no, insurance on the loan yes where it protects the rental income. When deductible charges exceed gross receipts, the difference is a déficit foncier, a rental deficit, which can in defined conditions be set against your other French income and carried forward; when the flat is your only French income, the deficit mechanics interact with the non-resident minimum rates examined below, so compute the deficit carefully rather than assuming it wipes out the French bill automatically.

Your position as landlord also shapes which charges even arise. Under Article 1720 of the Civil Code, the landlord must deliver the property in good repair of every kind and carry out, during the lease, all repairs that become necessary other than minor tenant repairs, while Article 1719 of the Civil Code obliges the landlord to deliver the property, to maintain it fit for the agreed use and, for a main home, to supply a decent dwelling. Money you spend to meet those landlord duties — fixing the boiler you own, repairing the roof share charged through the co-ownership, bringing the electrics back to standard — is the natural core of deductible charges. Money the tenant should bear — day-to-day upkeep, minor wear, charges recoverable as charges locatives — is not your deduction unless you bore it for the tenant and genuinely could not recover it. British owners who manage from abroad through an agent should therefore check the agent’s annual statement line by line: recoverable service charges passed to the tenant, non-recoverable owner charges, insurance, fees and works must be separated, because only the owner column feeds return No 2044. A frequent and expensive mistake is to deduct the gross co-ownership bill including the tenant’s share, or to deduct British letting-agent fees for the French flat without checking that they relate to management of that property; both invite reassessment with penalties.

A worked comparison makes the choice concrete. Take a British-resident owner letting an unfurnished two-bedroom flat in Nantes for 14,400 euros a year. Under micro-foncier, the taxable base is 14,400 minus 30 per cent, or 10,080 euros, with no further deduction. Under the régime réel, suppose insurance of 350 euros, managing agent’s fees of 1,150 euros, non-recoverable co-ownership charges of 1,800 euros, property tax (taxe foncière) where deductible of 1,100 euros, and loan interest of 2,400 euros: total charges of 6,800 euros leave a taxable base of 7,600 euros, nearly 2,500 euros lower than micro-foncier, and the saving compounds once the minimum non-resident rates and the solidarity levy apply on top. Reverse the facts — no mortgage, 14,400 euros of rent, 1,200 euros of charges — and micro-foncier’s 10,080 euros beats the réel base of 13,200 euros, so simplicity and saving point the same way. The option is exercised on the return, it binds you for the year, and switching regimes to chase the lower base each year without respecting the exclusions and thresholds is exactly what triggers computer selection for review. Calculate both bases every year before filing, keep the workings, and file the one the law allows — that single discipline halves most disputes before they start.

II. The two non-resident extras and your defences: minimum rates, solidarity levy, treaty credit and how to challenge the bill

A. The 20 and 30 per cent minimum rates, the average-rate escape, and the 7.5 per cent solidarity levy

French residents pay income tax on rental profit at the progressive scale; non-residents pay under the same scale but with a floor. Article 197 A of the General Tax Code provides that for persons without a French tax domicile receiving French-source income, “l’impôt ne peut, en ce cas, être inférieur à un montant calculé en appliquant un taux de 20 % à la fraction du revenu net imposable inférieure ou égale à la limite supérieure de la deuxième tranche du barème de l’impôt sur le revenu et un taux de 30 % à la fraction supérieure à cette limite”, meaning the tax cannot be less than 20 per cent on the part of net taxable income up to the top of the second bracket and 30 per cent above it, with reduced 14.4 and 20 per cent rates for income arising in the overseas departments. The same article then offers the escape: “lorsque le contribuable justifie que le taux de l’impôt français sur l’ensemble de ses revenus de source française ou étrangère serait inférieur à ces minima, ce taux est applicable à ses revenus de source française”, so where you show that the French tax rate on all your worldwide income would be lower than those floors, that lower average rate — the taux moyen — applies to your French income instead. The Conseil d’État restated the mechanism in a 2023 decision: “les revenus de source française perçus par des non-résidents sont passibles de l’impôt sur le revenu dont le montant ne peut être inférieur à celui qui résulterait de l’application de taux d’imposition minima prévus au a de l’article 197 A du code général des impôts”, adding that “lorsque ces contribuables justifient que le taux moyen d’imposition résultant de l’application du barème progressif sur l’ensemble de leurs revenus de sources française et étrangère, pensions alimentaires déduites, est inférieur à ces taux minima, il est fait application de ce taux sur les revenus de source française imposables” (CE, 3 February 2023, No 468904). The same decision refused to send to the Conseil constitutionnel the argument that this system discriminates between non-residents, holding the question not serious — so the minima stand, and the taux moyen is your remedy, not a constitutional challenge.

For a British owner, the practical consequence is direct. If your only income were the 7,600 euros of net rental profit in the Nantes example, the progressive scale alone might produce a low bill, but the 20 per cent floor imposes roughly 1,520 euros before the solidarity levy, unless the taux moyen reduces it. Claiming the taux moyen means declaring your worldwide income — British salary, British pension, British rental income, everything — so the administration can compute the average rate, exactly as the official guidance says: worldwide income must be declared to determine the rate. British owners often hesitate to disclose their full British income to France, but there is no half-measure: without the worldwide figures, the floor applies in full. Since Brexit, British residents remain eligible for the taux moyen because the article extends the supporting sworn-statement procedure to taxpayers domiciled in a State that has signed with France an administrative assistance or mutual recovery convention, which the United Kingdom has; keep your P60, pension statements and Self Assessment calculation, convert sterling with a consistent annual rate, and attach the sworn statement (déclaration sur l’honneur) while you gather the supporting documents. Owners with modest worldwide income routinely cut the French bill by a third or more this way; owners with high British income gain nothing and should not file worldwide figures speculatively without advice, since the declared figures can be used in later reviews.

The second extra is social: the prélèvement de solidarité, a 7.5 per cent solidarity levy on property income that applies to non-residents on top of income tax. Article 235 ter of the General Tax Code institutes “Un prélèvement de solidarité sur les revenus du patrimoine mentionnés à l’article L. 136-6 du code de la sécurité sociale”, and Article L. 136-6 of the Social Security Code lists among the property income subject to the contribution “Des revenus fonciers”, rental income. Its I bis extends the charge to persons not domiciled in France on the net amount of the income described in Article 164 B(a) used for income tax. Two recent decisions settle how far that goes for landlords like you. First, the Conseil d’État held in March 2026 that “sont assujetties au prélèvement de solidarité prévu au 1° de l’article 235 ter du code général des impôts les personnes physiques non-résidentes, à raison des loyers qu’elles perçoivent, issus de la location d’immeubles situés en France”, rejecting the argument that rents taxed as business profits rather than revenus fonciers escaped the levy (CE, 13 March 2026, No 503496). Your unfurnished rents are squarely inside that holding. Second, the Versailles administrative court of appeal confirmed, for Swiss-resident owners of French rental property invoking European social-security coordination after the famous de Ruyter case, that the historic 2 per cent solidarity levy on 2013–2014 French-source revenus fonciers was properly maintained: “M. et Mme C… ne sont pas fondés à soutenir que c’est à tort que le tribunal n’a pas prononcé la restitution du prélèvement de solidarité de 2% dont ils se sont acquittés à raison des revenus fonciers de source française qu’ils ont perçus au titre des années 2013 et 2014”, because none of the funds financed by that levy fell within the European social-security coordination regulation (CAA Versailles, 16 March 2021, No 19VE03537). The lesson for British owners after Brexit is clear: the general social contributions (CSG and CRDS) linked to health and family benefits follow different affiliation logic and are often not due where you are insured in the United Kingdom, but the solidarity levy, which finances non-contributory solidarity funds, is due on your French rents even as a British resident, and European-law arguments that recovered CSG and CRDS for affiliated cross-border workers do not recover the solidarity levy. Budget 7.5 per cent of the net rental profit for it, check that the assessment applies it to the net rather than the gross, and do not confuse a successful CSG refund claim with an exemption from the levy.

B. Getting credit in Britain for the French tax, the Paris practical note, and how to challenge an excessive bill

Paying in France is only half the story; the treaty must then prevent you paying twice. The mechanism is Article 24 of the France–United Kingdom treaty of 19 June 2008, which eliminates double taxation by giving the residence State — here the United Kingdom — a foreign tax credit for the tax properly levied by the situs State on the French rental profit, within the limit of the British tax attributable to the same income. Concretely, you report the gross French rent and the French tax paid on your British Self Assessment foreign pages, convert both with HM Revenue & Customs’ approved yearly or spot rates applied consistently, and claim Foreign Tax Credit Relief up to the British liability on that rental income; any French tax above the British tax on the same income is not refunded by Britain, which is why computing the French base correctly — micro versus réel, deficit use, taux moyen, correct levy base — matters as much as the credit itself. Keep the French avis d’imposition (assessment notice) as the prime exhibit: HM Revenue & Customs will ask for it, and the French administration will ask for your British documents if you claim the taux moyen, so the two files must tell the same story in figures. A common and costly mismatch is to declare the net profit in one country and the gross rent in the other, or to convert sterling and euros at different rates in each return; reconcile both returns to the same rent roll and the same exchange rate before filing either. Where the French assessment is later reduced on challenge, you must correct the British credit claim for the same year, and where the British credit is restricted, the excess French tax remains a real cost — another reason to get the French calculation right first time rather than relying on the credit to absorb errors.

A short Paris and Île-de-France note is warranted because so many British-owned French flats sit in the capital region and the local rules change the economics. First, the Paris, Plaine Commune and several inner-suburb zones apply rent control (encadrement des loyers) to new unfurnished leases and renewals, capping the rent by reference to a median rent per square metre plus a limited supplement for genuine extras; an above-ceiling rent can be referred by the tenant to the departmental conciliation commission and then the court, which can cut the rent and order repayment of the excess, directly shrinking the gross receipts your French tax is computed on. Second, service des non-résidents handling differs in practice: non-resident returns are processed centrally, online filing from a British address with no French bank account requires an impots.gouv.fr account linked to a recognised payment method for any balance, and correspondence goes to the address you declare, so keep a reliable French correspondence address, often your managing agent’s office with a proper mandate, and check the online mailbox rather than waiting for post in Britain. Third, the competent court for a challenge is the tribunal administratif of the place of taxation — for Paris property, Montreuil in most non-resident cases — and Paris-area co-ownership charges, concierge costs and building works are scrutinised closely because the amounts are high; label every charge as owner or tenant share before it reaches return No 2044. None of this requires a separate local article: it is simply the Paris layer of the same national calculation, and getting it wrong in Paris costs more because the rents and charges are larger.

When the French bill is wrong, the challenge follows the ordinary tax-litigation ladder, and each rung has a deadline you must not miss. Start with a réclamation contentieuse, a formal written claim to the tax office that issued the assessment, setting out the legal basis — wrong category, micro applied where réel was elected, disallowed charges that Article 31 allows, minimum rate applied where the taux moyen was claimed with worldwide figures, solidarity levy computed on the gross instead of the net — and attaching the lease, rent roll, invoices, agent statements, worldwide income proof and the treaty article relied on; the claim must generally be filed by 31 December of the second year after the assessment year, and it suspends enforced collection only if you apply for sursis de paiement with guarantees. If the administration rejects the claim expressly or by six months of silence, appeal to the tribunal administratif within two months of the rejection, where the judge reviews the legal basis of the assessment de novo and the cases quoted in this article — the March 2026 Conseil d’État on the levy’s scope, the February 2023 Conseil d’État on the minimum rates and the average rate, the Versailles ruling on the solidarity levy — are the authorities the reporting judge will actually read. Further appeal lies to the cour administrative d’appel and, on points of law, to the Conseil d’État, while genuine double taxation that survives both domestic assessments can be taken to the mutual agreement procedure under the treaty, where the two tax authorities negotiate which State gives way. Throughout, never stop filing and never stop paying the undisputed part: a taxpayer who files every year, pays what is clearly due and challenges only the disputed supplement with documents is treated differently — in penalties, in interest and in credibility — from one who simply stops engaging from London. Interest for late payment and penalties for inaccurate returns compound quickly on rental files because the same error repeats every year until corrected, so challenge the first wrong assessment, not the fifth.

Conclusion

Living in Britain after Brexit does not take your French flat outside French tax: France taxes the rent because the building is in France, under Articles 4 A and 164 B and Article 6 of the 2008 treaty, and the United Kingdom relieves the resulting double taxation by credit rather than by exemption. Your net profit is gross rents minus real charges under Articles 28 and 31, or gross minus 30 per cent under the micro-foncier of Article 32 where receipts stay within 15,000 euros; the non-resident floor of 20 and 30 per cent in Article 197 A applies unless your declared worldwide income earns you the lower average rate confirmed by the Conseil d’État in February 2023; and the 7.5 per cent solidarity levy under Article 235 ter and Article L. 136-6 applies to your net French rents as the Conseil d’État confirmed in March 2026, with no European-law refund on the Versailles authority. File return No 2042 with case 4BE for micro-foncier or with annexe 2044 for the actual-expenses regime, declare worldwide income whenever the average rate helps, claim the British credit on the same figures, keep every invoice and statement, and challenge the first wrong assessment through a documented claim and, if needed, the administrative court. Done in that order, the French flat remains what it should be: a sound investment with a predictable, verifiable and contestable tax bill, not an annual surprise from across the Channel.