Since Brexit, thousands of British owners have kept their French second home and put it on Airbnb or a similar platform to cover its running costs. The income is welcome, but the legal framework around short holiday lets in France has hardened considerably, and the reform of November 2024 made it harder still. A British owner who lists a flat in Paris, Bordeaux, Lyon or a strained coastal town without the right registration, the right municipal permission and the right tax return can face administrative fines of up to 10,000 euros for a missing declaration, 20,000 euros for a false one, 15,000 euros for exceeding the permitted letting days, and a civil fine for unlawful change of use, on top of back tax with penalties. This guide explains, in plain English and with the exact legal texts, how to let your French second home lawfully after Brexit: the national registration every host must complete, the change-of-use permission (autorisation de changement d’usage) that secondary homes need in regulated towns, the French tax on furnished-rental income whether you live in France or remain UK resident, the tourist tax your guests owe, and the practical routes for challenging a fine, a tax reassessment or a delisted advert from across the Channel.

I. Putting your French second home on a holiday-let platform lawfully: registration and change-of-use permission

The starting point is a distinction French law draws relentlessly and British owners often miss: your main home (résidence principale, the dwelling where you actually live most of the year) is treated leniently, while a secondary home (résidence secondaire, which is what your French house normally is if your life remains centred in the United Kingdom) faces the full weight of the holiday-let rules. Everything that follows is written for the secondary-home case, which is the strict one. If you genuinely live in the French property as your main home, some of the permissions below do not apply to you, but the registration duty still does.

A. Registering your holiday let and showing the declaration number on every advert

French law gives a precise definition of what you are doing when you list the property: a meublé de tourisme, a furnished villa, flat or studio let exclusively to the tenant, offered to passing guests who do not take up residence there, for stays billed by the day, week or month. That definition comes from Article L. 324-1-1 of the Tourism Code (Code du tourisme), and it is worth keeping in mind because every obligation that follows hangs on it. If your arrangement matches that description, you are a holiday-let host in the eyes of French law, whatever the platform calls you.

Before your first guest arrives, the same article requires you to file a prior declaration (déclaration préalable) through a national online service, the téléservice national. The declaration states whether the property is your main home, and on receipt of a complete file the service immediately issues an electronic acknowledgement carrying a declaration number (numéro de déclaration). That number must then appear in every advert for the property: Article L. 324-2-1 of the Tourism Code provides that the intermediary or platform publishes, in every advert relating to the let, that declaration number, expressed in the text as follows: “Elle publie, dans toute annonce relative à ce meublé, ce numéro de déclaration.” Platforms are separately obliged to inform you of these declaration and permission duties and to obtain from you, before the advert goes online, a sworn statement (déclaration sur l’honneur) that you comply, saying whether or not the dwelling is your main home. In practice, Airbnb and its competitors now ask for the number and block or delist adverts that lack it, because they face duties of their own.

The declaration is not a mere formality. The commune (municipality) where the property sits receives your file automatically and uses it to police the rules, and the fines for getting this step wrong are administrative fines imposed by the commune itself. Under paragraph V of Article L. 324-1-1, anyone who fails to comply with the declaration duties faces an administrative fine of up to 10,000 euros, while anyone who makes a false declaration or uses a false declaration number faces up to 20,000 euros. The familiar tolerance that lets a main home be let for up to 120 days a year does not help the British second-home owner: the statute caps at one hundred and twenty days per calendar year the short letting of a holiday let declared as the host’s main home, and even that ceiling can be lowered to ninety days by a reasoned decision of the municipal council (see Article L. 324-1-1 of the Tourism Code). Exceeding the permitted number of days exposes you to a civil fine of up to 15,000 euros. Because your French house is a secondary home, you cannot shelter behind the 120-day allowance at all: the allowance only ever covers a main home, and every short let of a secondary home in a regulated town must be justified by a permission, which is the subject of the next section.

One more confusion to clear up at this stage: the optional star rating (classement) that bodies such as the former Gîtes de France network used to award has nothing to do with permission. A classification decision describes the comfort of the property; it does not authorise anything. The Court of Cassation (Cour de cassation) said so in unmistakable terms on 27 June 2024, in a case brought by a commune against a tenant and a management company who argued that their classification decision authorised the short lets: Third Civil Chamber, 27 June 2024, appeal no. 23-13.131, holding that “En statuant ainsi, alors qu’une décision de classement en meublé de tourisme ne peut se substituer à l’autorisation de changement d’usage prévue à l’article L. 631-7 du code de la construction et de l’habitation, la cour d’appel a violé les textes susvisés.” In other words, a classification decision cannot stand in for the municipal change-of-use permission. Pay for a classification if you want the marketing benefit, but never mistake the certificate for a permit.

B. When Paris, Lyon, Bordeaux and other strained towns demand a change-of-use authorisation

The heaviest obligation is the change-of-use authorisation (autorisation de changement d’usage). Under Article L. 631-7 of the Construction and Housing Code (Code de la construction et de l’habitation), in the communes listed by decree, generally the large cities and the areas where housing is scarce, turning a residential property into anything else needs the prior permission of the local authority. Since the reform, the statute states the position for holiday lets bluntly: letting furnished residential premises as a holiday let is itself a change of use. In plain terms, each short let of your secondary home in Paris, in the inner suburbs, in Lyon, Bordeaux, Marseille, Nice, the Basque coast towns and dozens of other listed communes is, in law, a conversion of housing into a quasi-hotel, and it needs permission before the first guest, not after the first complaint.

The permission is granted by the mayor of the commune where the building stands, and it can come with strings attached. Article L. 631-7-1 of the same Code provides that “L’autorisation préalable au changement d’usage est délivrée par le maire de la commune dans laquelle est situé l’immeuble, après avis, à Paris, Marseille et Lyon, du maire d’arrondissement concerné.” In other words, the mayor issues the permission, with the opinion of the district mayor in Paris, Marseille and Lyon. The article adds that “Elle peut être subordonnée à une compensation sous la forme de la transformation concomitante en habitation de locaux ayant un autre usage.” That is, the permission may be conditional on compensation through converting other premises back into housing. That compensation (compensation) mechanism is what makes Paris so forbidding in practice: to convert a flat into a full-time holiday let, the owner must typically fund the conversion of an equivalent commercial surface back into housing in the same district, a condition far beyond the means of an ordinary British second-home owner. The authorisation is personal to its holder and dies with the end of the activity, unless it was granted against compensation, in which case it attaches to the property itself. Note also that time does not cure the breach: the statute expressly provides that the use of the premises is in no case affected by the thirty-year prescription, so a flat let unlawfully for decades does not become lawful by endurance. And agreements concluded in breach of Article L. 631-7 are void as of right: “Sont nuls de plein droit tous accords ou conventions conclus en violation du présent article.” Voidness as of right is the rule, which puts management mandates and even platform contracts on fragile ground where the underlying use is unlawful.

The courts enforce this scheme vigorously, and two decisions of the Court of Cassation set the boundaries every British owner should know. The first is the 27 June 2024 decision already cited, which quashed a court of appeal ruling that had treated a holiday-let classification as a substitute for the municipal authorisation. The second, Third Civil Chamber, 9 November 2022, appeals on the Paris change-of-use fines, restates the core prohibition: “Aux termes de l’alinéa 6 du même article, le fait de louer un local meublé destiné à l’habitation de manière répétée pour de courtes durées à une clientèle de passage qui n’y élit pas domicile constitue un changement d’usage au sens de cet article.” Repeated short lets to passing guests are therefore a change of use. The decision recalls the sanction: “Selon l’article L. 651-2 du même code, toute personne qui enfreint les dispositions de l’article L. 631-7 ou qui ne se conforme pas aux conditions ou obligations imposées en application de cet article est condamnée à une amende civile.” Infringers face a civil fine. The same decision usefully draws the line around intermediaries: an agent whose business is merely making furnished properties available for rent, or a platform providing the digital marketplace, does not itself commit the change of use and does not incur that particular civil fine, though platforms have their own separate duties under Article L. 324-2-1. For the British owner, the message is that responsibility sits squarely with the person letting the property, including a non-resident owner acting through a local manager: instructing a concierge service does not transfer the legal risk.

There is, however, a door that some communes have opened. Article L. 631-7-1 A of the Construction and Housing Code allows a municipal council to create a temporary change-of-use authorisation scheme under which an individual or company may let residential premises as a holiday let on conditions the council sets, which may cover the length of rental contracts, the physical characteristics of the property and its location in light of the housing market and the need not to worsen the housing shortage. Where your commune has adopted such a scheme, a time-limited authorisation is a realistic route to regularise a secondary home, and it should be the first thing your French adviser checks. Where no such scheme exists and the commune enforces strictly, letting a secondary home short-term in a listed town may simply not be available, and the lawful alternatives are a classic long-term unfurnished lease, a medium-term furnished lease such as the one-year furnished tenancy or the mobility lease (bail mobilité) for students and mobile workers, or selling. Before signing anything, also read the building rules: in a co-owned building (copropriété, the French equivalent of a leasehold block with shared areas), the co-ownership regulations (règlement de copropriété) often restrict or forbid short-term guest turnover, and neighbours can sue to stop lets that breach them, independently of anything the mayor decides.

II. Paying French tax on the rent and challenging fines and back-tax bills

Tax is where British owners most often come unstuck, because three systems overlap: the French tax on the rental income itself, which France always claims first on French property; the French social levies that may sit on top of the income tax; and the British tax return, on which the same income must also be reported with relief for the French tax under the double tax treaty. Add the tourist tax collected from your guests, and the picture is complete. Each layer is manageable if taken in order.

A. Declaring furnished-rental income in France, whether you live in France or remain UK resident

First, establish where you are taxable. If your everyday life, your family home or the centre of your economic interests is in France, you are likely to be treated as having your tax home (domicile fiscal) in France. Article 4 B of the General Tax Code (Code général des impôts) treats as having a French tax home those with their household or principal residence in France, alongside those who carry on a professional activity in France otherwise than incidentally and those whose centre of economic interests is in France. If your life remains centred in Britain and you merely visit the French house, you are normally UK tax resident and French non-resident, but that does not exempt the rent: French-source rental income is taxable in France in either case, and the treaty divides the taxing rights accordingly.

The treaty point matters because it decides which country has the first claim. Under the France-United Kingdom double tax convention, income from immovable property, which includes furnished-holiday-let rents, stays taxable in the country where the property sits, so France taxes the rent and the United Kingdom must then give relief against double taxation for its own residents. The official treaty texts and their dates of effect are published by the British government at GOV.UK, France tax treaties, and any adviser working on your file should check the version in force for the year concerned rather than assuming the treaty eliminates one of the two liabilities. It does not: you will file in both countries, pay in France first, and claim the corresponding relief in Britain.

On the French side, furnished letting is taxed as industrial and commercial profit (bénéfice industriel et commercial, abbreviated BIC), not as ordinary unfurnished rental income, which changes the declaration forms and the allowances. Most British owners of a single second home fall under the simplified micro-BIC scheme (régime micro-BIC), provided their annual takings stay below the ceiling. Article 50-0 of the General Tax Code sets the ceiling for ordinary holiday lets at 15,000 euros excluding tax per year and grants a flat-rate expense allowance (abattement) of 30 per cent of the takings, with a minimum allowance of 305 euros: the taxable profit is the takings minus the allowance, and the allowance may not be less than 305 euros even on tiny revenues. Classified lets and rural guest rooms can benefit from different, more generous ceilings, which is one reason the optional classification still has some tax interest, but the standard British second home listed on a platform falls under the 15,000 euro and 30 per cent rule. If your takings exceed the ceiling, or if your real expenses such as agency fees, repairs, insurance, co-ownership charges and loan interest exceed the flat-rate allowance, you may elect for the real-expenses scheme (régime réel), under which deductible costs are set against the rent and depreciation (amortissement) of the furniture and fittings, though not of the land, can materially reduce the bill. The election is a calculation to make with figures, not a reflex, and it binds you for several years.

Non-resident owners face one further mechanism that regularly produces shock bills. Article 197 A of the General Tax Code provides that for persons without their tax home in France who receive French-source income, the tax may not be less than an amount computed by applying a rate of 20 per cent to the portion of net taxable income at or below the top of the second income-tax band and 30 per cent above it — the tax may not be less than 20 per cent on the slice of net taxable income up to the top of the second band of the income-tax scale and 30 per cent on the slice above it. There is a safety valve: where you can show that the French tax on all of your French and foreign income together would be lower than those minimum rates, that lower overall rate applies to your French income instead. Owners from a European Union Member State, or from a state that has signed an administrative-assistance or recovery-assistance convention with France, which includes the United Kingdom, may attach a sworn statement to that effect pending production of the supporting documents. In practice this means a British non-resident with modest worldwide income should not simply accept a 20 per cent minimum: the worldwide-rate claim (taux moyen) often halves the bill, but it must be affirmatively made with evidence of global income.

French social levies (prélèvements sociaux) may then apply on top of the income tax, at rates and under exemption conditions that depend on your country of residence and on the social-security system to which you belong, a point on which the Franco-British position since Brexit is technical and fact-sensitive. Do not guess this line of the return: have it checked against the current guidance of the French tax administration at impots.gouv.fr before you file, because an error here is what most often triggers an automated reassessment. Finally, the guest side: the tourist tax (taxe de séjour) is owed by the guest, not by you, but you or your intermediary collect it. Article L. 2333-34 of the General Code of Local Authorities (Code général des collectivités territoriales) requires electronic platforms that act as payment intermediaries for non-professional hosts to pay the tax they collect to the municipal revenue officer twice a year, no later than 30 June and 31 December — platforms acting as payment intermediaries pay the tourist tax they collect to the municipal revenue officer twice a year, by 30 June and 31 December. If you take direct bookings outside a platform, you collect and remit the tax yourself on the dates set by the municipal council, and the nightly rate depends on the category of the accommodation and the commune’s vote, so check the mairie’s current tariff each year rather than copying last year’s figure.

B. Challenging a fine, a tax reassessment or a delisted advert from the United Kingdom

Enforcement usually arrives in one of four envelopes: a commune’s formal notice (mise en demeure) followed by a fine for missing registration, false declaration or excess letting days; a court summons at the commune’s request for the civil fine for unlawful change of use, with a possible order to return the property to residential use (retour à l’usage d’habitation) under a daily penalty (astreinte) running per day and per square metre; a tax reassessment (proposition de rectification) from the non-residents tax office putting back-tax, interest and surcharges on several years of undeclared platform income, which the administration increasingly detects through the data platforms must now transmit to communes and through international information exchange; or a platform message suspending your advert for want of a declaration number. Each has its own remedy, and distance does not remove any of them, though it makes organisation essential.

Start with the facts and the file. For a municipal fine, check the three points on which these cases are won or lost: was the property genuinely your secondary home or can you prove it was your main home for the period, with tax notices, utility bills and residence evidence to match the declaration; were the letting days counted correctly, given that the commune may demand the number of days let and you must answer within one month, reminding it of the address and the declaration number; and was the procedure respected, including the deliberation authorising the local scheme and the formal notice. For a change-of-use prosecution, the defences that work are narrow but real: the premises were never residential in the relevant sense, the lets were long-term or medium-term tenancies rather than passing-guest stays, or a temporary authorisation scheme existed and was applied for. What does not work, since the June 2024 decision, is waving a holiday-let classification certificate as if it were a permit. For a tax reassessment, answer within the stated deadline, which is short, reconstruct the takings year by year from platform statements and bank records, verify whether the micro-BIC ceiling or the real-expenses scheme serves you better for each year still open, and, for non-residents, raise the worldwide-rate claim with proof of global income rather than letting the 20 and 30 per cent minimum rates apply by default. Keep everything: platform payout histories disappear or become hard to retrieve, and the owner who can document each year beats the owner who reconstructs from memory.

Then use the proper channel for each decision. Administrative fines from the commune are contested before the administrative courts, beginning with a written challenge that sets out facts, law and evidence, and respecting a strict time limit that runs from notification, so diary the date the letter arrived, not the date you opened it on your next visit. Civil fines sought by the commune go before the president of the judicial court (tribunal judiciaire) sitting in the fast-track procedure on the merits (procédure accélérée au fond), where representation by a French lawyer is in practice indispensable and where the judge can also order the return to residential use under penalty. Tax reassessments go first to the tax office in a written claim (réclamation) engaging with each adjustment line by line, and then, if the administration maintains its position, to the administrative court. Platform suspensions are resolved fastest: supply the declaration number, correct the advert, complete the sworn statement, and separately regularise the position with the mairie so the next automated check clears you. In every route, appointing a French address for service, instructing a French lawyer or tax adviser, and granting a power of attorney where needed avoids the classic failure of learning about a deadline after it has expired. British owners should also remember that ignoring a French fine or tax bill does not contain it in France: within Europe, cross-border recovery instruments exist, and an unpaid judgment can resurface at the worst moment, typically during a sale, when the notary (notaire, the public officer who handles conveyancing) settles all charges before distributing the price.

A final word on prevention, which after Brexit matters more than cure. If you are buying or already own through a French property company (société civile immobilière, abbreviated SCI, a civil company commonly used by families to hold French property), have the manager check that short letting is compatible with the company’s purpose and the co-ownership rules before listing. If you spend long periods managing the property in person, remember that stays in the Schengen area are capped for British visitors and that hands-on management over many months can raise residence and social-security questions well beyond this guide. And if the numbers show that lawful short letting in your commune requires a compensation payment you cannot fund, pivot early to a compliant medium or long-term tenancy rather than letting unlawfully while hoping for tolerance: the current statutes give communes data, powers and fines on a scale that makes systematic unlawful letting a predictable loss.

Conclusion

A British-owned French second home can still be let to holidaymakers lawfully and profitably after Brexit, but only within a framework that is now fully codified and actively enforced. Register the property on the national teleservice and display the declaration number on every advert; accept that in a listed commune each short let of a secondary home is a change of use needing the mayor’s prior authorisation, with compensation where the council requires it, and that no classification certificate replaces that permission; declare the rents as furnished-rental profits in France, pay first in France under the treaty’s situs rule, then claim relief in Britain; collect the tourist tax for the commune; and keep the records that make any challenge possible. Where a fine or a reassessment has already landed, challenge it on the facts, in the right court, and within the deadline, from the United Kingdom if necessary through a French representative. Taken in that order, registration, permission, tax and defence turn an enforcement risk back into what the second home was meant to be: an asset that pays its way.