You moved to France for the light, the space, or the slower mornings, and then a thick envelope arrives from the French tax office. It is headed proposition de rectification, which is the formal notice by which the administration tells you it intends to correct your tax return, and it usually ends with an extra bill for tax, late interest and penalties. Your first reflex may be to ring HMRC in London, or to assume that because you already pay tax in Britain you owe nothing in France. Both reflexes can cost you money. Since Brexit you are a third-country national in France, the French administration checks newcomers closely, and the reassessment procedure runs on short, strict deadlines: miss the first one and you lose your best chance of stopping the bill before it becomes final. This guide explains, in plain English, how the French contradictory reassessment procedure works, how to attack the finding that your tax home is in France, how to use the France-United Kingdom double tax treaty of 2008, and how to challenge the tax, the interest and the penalties step by step, including in court. Every French term is explained as it appears, and every decisive rule is quoted from the official text so you can check it yourself on Légifrance.

I. How to answer the French reassessment notice and protect your rights from day one

A. Read the proposition de rectification carefully and reply inside the thirty-day deadline

The proposition de rectification is the starting point of almost every French tax dispute. It is the letter in which the tax inspector sets out what he or she considers wrong in your return, year by year, the legal basis relied on, and the additional amounts claimed. Under the contradictory procedure, the administration must send you this reasoned notice before it can recover anything, and the law states the requirement in plain terms: 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. In other words, the notice must be reasoned enough to let you understand the complaint and answer it. That single sentence is your first line of defence. If the letter merely asserts that you are resident in France, or recalculates your income without saying which documents or which legal provision it relies on, the reasoning may be defective, and defective reasoning can lead a court to cancel the whole reassessment. Read the notice with a pen and check four things: which tax and which years are covered, the exact legal provisions cited, the figures and the documents relied on, and the name and contact details of the inspector, because all later correspondence goes through that office.

The general rule for tax reassessments on British residents is the contradictory procedure, which the code defines as follows: les rectifications correspondantes sont effectuées suivant la procédure de rectification contradictoire définie aux articles L. 57 à L. 61 A. Contradictory means what it says: the administration must hear you before it taxes you. You normally have thirty days from receipt to send written observations or to accept the reassessment, since le délai accordé aux contribuables pour répondre aux demandes de renseignements, de justifications ou d’éclaircissements et, d’une manière générale, à toute notification émanant d’un agent de l’administration des impôts est fixé à trente jours à compter de la réception de cette notification. Thirty days is short, especially if you need documents from the United Kingdom, so use the extension the statute gives you: if you ask before the deadline expires, you get thirty more days to prepare a serious reply. Send that extension request immediately by registered letter with acknowledgement of receipt, known in France as a lettre recommandée avec accusé de réception, or through your personal account on impots.gouv.fr, the official portal of the French tax administration, and keep proof of everything. Never let the deadline pass in silence, because silence counts as tacit acceptance and the tax is then assessed as proposed, with interest and penalties on top.

Your written observations should answer each point in the notice, in the same order, with numbered exhibits. Typical issues for a British household are easy to anticipate. The inspector may treat you as French tax resident from the year of arrival while you considered yourself still United Kingdom resident under the Statutory Residence Test. He may add back rental income from a London flat that you declared in Britain but omitted in France, or question why a pension lump sum taxed in the United Kingdom does not appear on the French return. He may apply social charges, the prélèvements sociaux, to income that a treaty or European rule exempts. For each item, state clearly whether you agree or disagree, give the legal reason, and attach the proof: tenancy agreement and council tax bills for the London address, removal company invoice, French utility contracts, school certificates, travel records, P60s and pension statements, and the corresponding pages of your British and French returns. Ask expressly for a meeting with the inspector, known as an entretien, because an oral discussion often narrows the dispute before positions harden. If you agree with part of the reassessment, say so explicitly and continue to contest the rest; a partial acceptance does not prevent you from fighting the remainder, and it stops interest running on the accepted part. If the administration rejects your observations, its reply must itself be reasoned, which gives you a second document to examine for flaws before the assessment, called the mise en recouvrement, makes the bill enforceable.

B. Attack the tax-home finding and make the France-United Kingdom treaty work for you

Most reassessments served on British residents stand or fall on one question: where is your tax home. The French domicile fiscal is not a vague notion; it is defined by statute, and the definition is deliberately broad: 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 ; to which the code adds a third alternative, the centre of economic interests in France. These three tests are alternatives, not cumulative: meeting any one of them is enough for the administration to treat you as French resident for the whole year. The first test, the foyer, is the one inspectors use most against British families, and the courts have given it a precise meaning. As the Paris judicial court put it in a recent tax-residence judgment: Le foyer s’entend du lieu où le contribuable habite normalement et a le centre de ses intérêts familiaux sans qu’il soit tenu compte des séjours effectués temporairement ailleurs en raison des nécessités de la profession ou de circonstances exceptionnelles. The same court adds the essential qualification: Le lieu de séjour principal du contribuable ne peut déterminer son domicile fiscal que dans l’hypothèse où celui-ci ne dispose pas de foyer. In practice, if your spouse and children live with you in France, the administration will say your foyer is in France even if you spend three days a week in London; business trips and temporary stays abroad do not move the family home. Conversely, if your family genuinely remained in Britain while you worked a fixed-term assignment in France, living in rented rooms and flying home most weekends, you can argue that your foyer stayed in the United Kingdom and that your French presence was temporary by professional necessity.

Build your residence file the way a judge will read it, criterion by criterion. For the foyer and the place of principal stay, produce the lease or title deeds of each home, utility bills across the full year, children’s school or nursery certificates, medical and insurance records showing where the family actually lived, and a day-count table supported by boarding passes, Eurostar bookings or employer travel logs. For professional activity, show where the work was physically done, not where the employer sits: a British employment contract does not prove British residence if you worked remotely from a house in the Dordogne five days a week. For the centre of economic interests, list bank accounts, investments, business directorships and the place where your assets are managed, because an inspector who cannot win on the family home often falls back on the money trail. Remember that France taxes its residents on worldwide income while the United Kingdom taxes under its own residence rules, so a split year, where each country claims you for the same months, is common in the year of the move. That overlap is exactly what the France-United Kingdom double tax treaty is for: its residence tie-breaker allocates dual residents to one State using successive tests such as the permanent home and the centre of vital interests, and its relief articles then decide which State taxes each category of income and how the other State eliminates double taxation, usually by credit. The courts apply treaties strictly, and the Court of Cassation recently recalled the discipline required: taxpayers who claimed treaty residence had to prove it and, in the judges’ words, doivent démontrer non seulement que les autorités suisses leur attribuent la qualité de résident fiscal en Suisse, mais également qu’ils ont cette qualité au sens de cette convention. The case concerned the Franco-Swiss treaty, but the lesson is general and applies equally to the Franco-British treaty: a certificate from HMRC or a British self-assessment is useful evidence, but it does not by itself decide the treaty question; you must show that you meet the treaty’s own definition of residence. Practical guidance on the British side, including how HMRC treats leavers and the relief available under the treaty, is published by the British government on gov.uk, which you should read alongside the French notices. A related explanation of how French judges test residence day by day is given in our guide for British couples living between the two countries, available at British Couples Split Between France and the UK: How to Prove Tax Residence After Brexit, which sets out the same proof methods in a family context.

II. How to challenge the bill, cut the penalties and avoid paying tax twice

A. Escalate inside the administration, then file the formal claim that suspends enforcement

If the inspector maintains the reassessment after your observations, you are not at the end of the road; you are at the start of the remedies the statute organises for you. The first is the departmental or national commission, a panel that gives an opinion on disputes about facts such as valuations, residence findings or business profits when disagreement persists. The mechanism is straightforward: Lorsque le désaccord persiste sur les rectifications notifiées, l’administration, si le contribuable le demande, soumet le litige à l’avis soit de la commission des impôts directs et des taxes sur le chiffre d’affaires prévue à l’article 1651 du code général des impôts or, depending on the tax, to one of the other specialised commissions the article lists. You must expressly request referral; it is never automatic. The departmental commission for direct taxes sits in each administrative court district and mixes magistrates, taxpayer representatives and senior officials, since Il est institué, dans le ressort de chaque tribunal administratif, une commission des impôts directs et des taxes sur le chiffre d’affaires. Its opinion is advisory, but in practice an opinion in your favour often leads the administration to drop or reduce the reassessment, and an unfavourable opinion at least tells you how the other side will argue in court. Prepare for the hearing as for a small trial: a short memorandum, a paginated bundle, and the three strongest exhibits rather than fifty pages of bank statements.

Once the tax is assessed and you receive the collection notice, the decisive step is the formal claim, called the réclamation contentieuse, sent to the tax office that assessed you. Practical guidance for drafting and filing that claim is published on service-public.fr, the French administration’s official public-service portal, and the claim can be filed from your account on the tax portal. State the tax, the years, the amounts, the legal grounds and the exact relief you seek, namely full or partial discharge, and attach everything, because documents produced for the first time only before the court may be looked at with suspicion. Crucially, combine the claim with a request to suspend enforced collection, the sursis de paiement, addressed to the public accountant handling recovery: while the administration examines your claim, bailiff action and bank seizures are normally paused, provided you set out sufficient guarantees if the amounts are large. Do not ignore the collection letters during this period; check every notice for the correct taxpayer name, address, tax, year and amount, since a material error in the recovery documents can itself support a challenge. If the administration rejects the claim expressly, or stays silent for six months, which counts as an implied rejection, you have two months to take the case to the administrative or judicial court depending on the tax. Mark these dates on receipt of each letter, because French tax litigation is unforgiving about time limits, and a late appeal fails whatever its merits.

At every stage, fight the penalties separately from the principal tax, because they often represent a third or more of the bill and judges cancel them more readily than the tax itself. Late payment automatically attracts late interest, and the code states the principle bluntly: Toute créance de nature fiscale, dont l’établissement ou le recouvrement incombe aux administrations fiscales, qui n’a pas été acquittée dans le délai légal donne lieu au versement d’un intérêt de retard. On top of that interest, the code adds surcharges graded by seriousness: Les inexactitudes ou les omissions relevées dans une déclaration ou un acte comportant l’indication d’éléments à retenir pour l’assiette ou la liquidation de l’impôt ainsi que la restitution d’une créance de nature fiscale dont le versement a été indûment obtenu de l’Etat entraînent l’application d’une majoration de : a. 40 % en cas de manquement délibéré ; b. 80 % en cas d’abus de droit au sens de l’ article L. 64 du livre des procédures fiscales, with eighty per cent also available for fraud and concealment. The forty per cent surcharge for deliberate failure is the one most often applied to British newcomers who omitted a London rent or a pension from the French return, and it is also the one most often defeated. Show that the omission was an honest mistake by a newcomer dealing with two tax systems in a foreign language: produce the British return where the same income was fully declared, the first French return prepared without professional help, correspondence asking your bank or pension provider for the figures, and the correction you filed as soon as you understood the rule. Courts regularly hold that ignorance of a complex foreign rule, without any concealment, is not deliberate failure. The same file that proves good faith on residence therefore serves twice, cutting both the tax and the surcharge. Note that reassessments routinely combine both, as one appeal court recorded where l’administration fiscale a remis en cause cet avantage et émis une proposition de rectification portant rappel de droits et pénalités. Always ask, in the alternative, for the surcharge to be cancelled even if the tax itself were upheld; judges can grant that alternative plea, and inspectors sometimes concede it in settlement discussions to save the principal.

B. Take the dispute to court and sort out the British side so the same income is not taxed twice

If the formal claim fails, the courtroom is a realistic option, not a last resort for the desperate. Income tax and most personal taxes go to the administrative court, the tribunal administratif, while wealth, inheritance and some registration duties go to the judicial court, the tribunal judiciaire; your rejection letter tells you which one and restates the two-month deadline. Draft the court application around three or four strong pleas rather than ten weak ones. First, procedural defects: an unreasoned proposition de rectification, a refused extension, observations left unanswered, or a commission referral wrongly denied. Second, the residence finding: walk the judge through the foyer, professional activity and economic interests tests with dated exhibits, and explain why the treaty tie-breaker allocates you to the United Kingdom for the disputed year. Third, the treaty characterisation of each income stream: pensions, rents, interest, dividends and capital gains each have their own treaty article, and taxing the wrong article is a winning plea. Fourth, the penalties: no deliberate failure, no concealment, disproportionate surcharge. Ask the court to order full discharge of the tax and, in the alternative, cancellation of the surcharges and interest. Proceedings are written, take a year or more, and cost less than most taxpayers fear; legal aid, called aide juridictionnelle, exists for modest incomes, and a focused file of thirty pages beats a chaotic bundle of three hundred.

In parallel, manage the British side, because even a complete victory in France leaves double taxation if HMRC has also taxed the same income without relief. The treaty eliminates double taxation mainly by the credit method: the residence State taxes the worldwide income and gives credit for the tax properly levied by the source State on the items the treaty lets it tax, such as rents from a London flat or certain pensions. Practically, this means keeping both returns consistent, claiming Foreign Tax Credit Relief in the United Kingdom for French tax on dual-claimed items, and claiming the treaty credit in France for British tax on the items France must relieve, each within its national time limit. If United Kingdom tax was withheld at source that the treaty forbids, for example on a pension that is taxable only in France, apply to HMRC for repayment with the treaty claim form and the French tax assessment as proof, rather than asking the French judge to refund British tax he has no power over. Keep a single bilingual schedule, year by year and income by income, showing the gross amount, the British treatment and the French treatment, so that neither administration can claim you are hiding the income from the other. And if the dispute concerns social charges on top of income tax, check the affiliation position first: a British pensioner with an S1, or a worker paying National Insurance in the United Kingdom under a posting certificate, may be exempt from French social charges on employment or replacement income, which removes a whole layer of the bill before the treaty credit even applies. Handle the two countries as one file with two fronts, and the reassessment that first looked like a catastrophe becomes a structured negotiation in which each plea, procedural, residence-based, treaty-based or penalty-based, independently reduces what you finally pay.

Conclusion

A French tax reassessment is frightening, but it is also a procedure with rules, and rules can be used. Answer the proposition de rectification within thirty days, ask for the extra thirty days at once, and reply point by point with exhibits. Contest the tax-home finding with dated proof of where your family lived, where you worked and where your money was managed, and force the analysis into the France-United Kingdom treaty rather than domestic law alone. Escalate through the commission, the formal claim with suspended collection, and then the court, fighting the surcharges as hard as the tax. Sort out HMRC in parallel so the same pound of income is not taxed twice. British residents who treat the reassessment as a structured file, with a calendar, a residence bundle and a treaty schedule, regularly see the bill reduced or cancelled, even when the first letter looked hopeless. Keep every envelope, every receipt and every filing confirmation, and get advice before the first deadline expires rather than after the last one has passed.

Need a quick opinion on your case

If you have just received a proposition de rectification, a tax bill or a penalty notice in France, our firm can review your file quickly. We offer a telephone consultation within 48 hours with a lawyer of the firm. Call +33 6 46 60 58 22 or write through our contact page with a copy of the notice and your most recent French and British tax returns.