A move to France does not automatically take a British family outside UK Inheritance Tax. Since 6 April 2025, the United Kingdom has replaced the old domicile-based approach to overseas assets with a long-term UK residence test. A person who has lived in the UK for at least 10 years in the relevant 20-year period can remain within the UK charge after moving abroad, including during a post-departure period. The exact result depends on the tax years counted, the date of the move, the assets in the estate and any applicable exemption.

France can also tax a succession under its domestic rules. The France–UK convention on inheritance taxes may allocate taxing rights or allow relief, but it is not a general promise that one country will ignore the estate. A French tax-residence certificate, a UK residence history, the location of each asset, a will and proof of tax paid may all be needed before the position can be resolved. The 2008 France–UK income-tax treaty should not be confused with the separate succession convention.

This guide answers the practical question for a British person who is settled, or becoming settled, in France: when can UK Inheritance Tax still apply, how does French succession tax interact with it, and what should the family prepare before a death? Tax exposure, civil succession, probate and the administration of a French estate are related but separate questions. Each must be mapped against the same date-of-death facts.

I. Will a British resident in France still pay UK Inheritance Tax after Brexit?

A. How the 10-year long-term UK residence test works after 6 April 2025

Inheritance Tax, usually shortened to IHT, is a transfer tax assessed on the value transferred at death and on certain lifetime transfers. It is not the same as income tax on a pension, Capital Gains Tax on a sale or French droits de succession, the French term for inheritance duties. A British passport does not by itself determine IHT. The principal questions are the deceased person’s long-term UK residence status, the situs of each asset, the nature of any trust or pension arrangement, and the exemptions and reliefs available to the estate.

The post-2025 starting point is the long-term UK resident, or LTR, test. HM Revenue & Customs explains the new framework in its official guidance on Inheritance Tax for a long-term UK resident. In broad terms, an individual is long-term UK resident for the relevant period where they have been UK resident for 10 consecutive tax years, or for at least 10 tax years in the previous 20 tax years. The language matters: this is a tax-year calculation, not a simple count of anniversaries since the person left Britain.

For the statutory foundation, the United Kingdom inserted the long-term residence rules into the Inheritance Tax Act 1984 through the Finance Act 2025. The enacted changes should be read with the current HMRC long-term UK residence guidance and the legislation in force on the date of death. An adviser should identify every UK tax year in the 20-year look-back window and record whether the individual was UK resident under the applicable Statutory Residence Test. A departure in the middle of a tax year may involve split-year treatment, but split-year treatment does not permit the estate to choose whichever part of the year produces the lower IHT result.

The post-departure tail is the point most often missed by British families in France. If the individual has the required UK residence history, they can remain treated as an LTR for a number of tax years after leaving the UK. The official guidance gives a graduated outcome: a person with 10 to 13 relevant UK-resident years can have a three-year tail; the tail then increases as the number of UK-resident years in the relevant period increases, reaching a longer period for a person with a deeper UK residence history. It is unsafe to translate the rule into “I moved to France, so my worldwide estate is now outside UK IHT”. The departure date starts the calculation; it does not finish it.

For example, assume that a British national moves permanently to France on 30 September 2025 after a long working life in the UK. The executor should not count only the years shown on a French residence permit. The file should identify the UK tax years before departure, any earlier years in the previous 20-year period, and the number of years for which the person remains LTR after departure. If death occurs during that tail, non-UK assets may still fall within the UK IHT charge. If death occurs after the tail has expired, the overseas-assets analysis can change, while UK-situs assets may remain exposed under the ordinary UK rules.

The practical calculation should be chronological. Create a schedule with one line for every UK tax year, from 6 April to 5 April, and note the residence result, the source of the result and the document proving it. Useful evidence may include P60s, Self Assessment returns, HMRC residence correspondence, employment records, tenancy agreements, travel calendars, school records, medical records and the date on which the family home became established in France. French tax returns, avis d’impôt (French income-tax notices) and a French tax-residence certificate can support the chronology, but they do not replace the UK residence analysis.

The type and location of the property then have to be listed separately. A house or flat situated in the UK is normally a UK-situs asset. A French house, French bank account, UK shares, investment funds, life-insurance policy, pension, trust interest or loan receivable may each require a separate classification. “Held through a company” is not a complete answer: the relevant asset may be shares in a company rather than the underlying house, and an anti-avoidance rule or a special regime may affect the result. A valuation at the date of death is also a separate exercise from identifying the applicable tax jurisdiction.

UK exemptions remain important. The current GOV.UK overview of Inheritance Tax explains the standard 40% rate and the ordinary nil-rate band of £325,000, subject to the conditions and changes stated on the official page. A residence nil-rate band may be available when a qualifying home passes to direct descendants, and an unused allowance may transfer between spouses or civil partners. Charitable gifts and transfers between spouses or civil partners can also be relevant. Those rules do not erase an LTR classification; they reduce or eliminate a charge only if the particular statutory conditions are satisfied.

The family should therefore ask three different questions rather than one. First, is the deceased an LTR on the death date, including any tail? Secondly, which assets are within the UK charge on that date? Thirdly, which exemption, relief, threshold or credit is available after the gross estate and debts have been calculated? A French move can alter the answer to the first question without changing the situs of a UK asset. Conversely, the end of an LTR tail may affect overseas assets without making a UK house or UK business interest disappear from the UK tax map.

B. How French residence and the France–UK succession convention change the result

French residence is legally relevant, but it is not a substitute for the UK LTR test. In French law, domicile fiscal means tax domicile. Article 4 B of the French General Tax Code lists the domestic indicators, including the home or principal place of stay, professional activity and centre of economic interests. The official text begins, “Sont considérées comme ayant leur domicile fiscal en France au sens de l’article 4 A :”. The complete Article 4 B of the French General Tax Code is available on Légifrance. A treaty tie-breaker may then modify the domestic conclusion for the tax covered by that treaty.

French succession tax uses its own connecting rules. Article 750 ter of the General Tax Code is the key domestic provision. It can bring the deceased’s worldwide assets into the French inheritance-tax base when the deceased was domiciled in France, can tax French-situs assets when the deceased was not domiciled in France, and can include worldwide assets received by an heir, legatee or donee who has been tax resident in France for at least six of the preceding ten years, subject to the text and treaty limitations. The current Article 750 ter text on Légifrance should be read with the date of death and the applicable treaty.

The French tax administration explains the treaty method in its official page on international succession conventions. It states, in substance, that the allocation generally depends on the deceased person’s residence and the location of the assets, not on the residence of the heirs. The impots.gouv.fr guidance on international inheritance-tax conventions also warns that the convention must be checked country by country. That is why a British heir living in France cannot obtain a reliable answer merely by saying, “the beneficiary lives in France”, or “the deceased was British”. Both propositions are incomplete.

The France–UK convention on estates has to be separated from the 2008 convention on income and capital gains. HMRC’s Inheritance Tax Manual guidance on the France–UK convention describes the practical allocation and credit procedure. The French administrative doctrine is set out in the BOFiP guidance for the United Kingdom succession convention. These are official administrative sources, not a replacement for reading the convention itself and the law applicable on the death date.

Where French tax is due on an asset and UK IHT is also charged on the same economic value, relief may be available by allocation under the convention or by a domestic credit. Article 784 A of the French General Tax Code provides the domestic credit in specified cases. Its wording is precise: “Dans les cas définis aux 1° et 3° de l’article 750 ter, le montant des droits de mutation à titre gratuit acquitté, le cas échéant, hors de France est imputable sur l’impôt exigible en France.” The official Article 784 A text on Légifrance immediately limits the credit to the French tax attributable to the relevant assets situated outside France. The credit is not necessarily a pound-for-euro or pound-for-pound refund of every amount paid abroad.

The BOFiP guidance gives a practical example for a person domiciled in France whose estate includes UK company shares. It explains that French tax can be calculated under the domestic rule and that UK tax paid may be taken into account under the convention, on request, within the stated limitation period. The administrative guidance refers to a five-year period for requesting the imputation in the relevant circumstances. The estate should preserve the UK assessment, the payment receipt, the asset valuation and the French calculation. A claim supported only by a bank statement, without the tax authority’s assessment, is likely to leave the administration unable to verify the amount and the asset concerned.

Forms and certificates matter. Depending on the direction of the claim, the French administration may require Form 2740 or related evidence to claim UK tax as a credit, while HMRC may require a French declaration or clearance certificate before recognising the treaty position. The exact form can change with the route and the date. The executor should ask the relevant office what document it expects and retain the request, the response and proof of submission. Do not assume that a notaire, the French civil-law notary who administers many French estates, has automatically filed the UK-side treaty claim.

A treaty can also produce a waiver rather than a credit, depending on the deceased person’s fiscal domicile and the situs assigned to the property. That distinction has a cash-flow consequence. A waiver may prevent a charge in the first country; a credit may require tax to be paid in one country before relief is granted in the other. The family should model both the legal allocation and the timing. A refund claim made after the statutory filing deadline may fail even where the underlying double-taxation argument is sound.

French rates and allowances must be calculated on the relationship between the deceased and each beneficiary. Article 777 of the General Tax Code states that transfer duties are fixed by tables according to the net share received by each person. Its opening words are, “Les droits de mutation à titre gratuit sont fixés aux taux indiqués dans les tableaux ci-après, pour la part nette revenant à chaque ayant droit :”. The Article 777 rate tables on Légifrance include progressive rates in the direct line and different rates for more remote relationships. Article 779 provides allowances, including the direct-line allowance in the situations described by the text; consult the Article 779 section on Légifrance rather than applying a generic online calculator.

Take care with the word “domicile”. It can describe a civil-law concept, a UK domicile concept in older material, or a tax-residence concept under French or UK law. The post-6 April 2025 UK regime deliberately uses long-term residence for the overseas-assets analysis. A document prepared under an older domicile model may still be evidence of the family’s history, but it cannot be treated as the current legal test without checking the date and the provision being applied.

II. How should a British resident in France organise the estate and challenge a double charge?

A. Which will, family and valuation documents should be prepared before death?

The first preparation is an asset-and-family file that can be understood by both a UK executor and a French notaire. It should state the date on which the person moved to France, each earlier UK residence period, the intended permanent home, nationality, marital or civil-partnership status, children, previous marriages, lifetime gifts, trusts, life insurance and pension nominations. It should list the gross value and location of every account, investment, property, loan, business interest and digital asset. Each line should have an owner, a beneficiary where relevant, a valuation source and the document proving the figure.

A will deals primarily with civil succession and the appointment of people to administer the estate. It does not by itself decide which country taxes the estate. The choice of law, jurisdiction, probate route and tax residence must be analysed separately. The EU Succession Regulation can be relevant to a French succession, but the United Kingdom is not a participating Member State for that Regulation. The judgment of the French Court of Cassation, First Civil Chamber, 18 November 2020, no. 19-15.438, illustrates why jurisdiction and the Regulation’s connecting provisions must be examined carefully in a cross-border succession dispute. It is not a substitute for the tax analysis and should not be read as a ruling that one nationality automatically determines the applicable law.

The family should ask whether one UK will, one French will, or coordinated documents are appropriate. A French will may need to be received or checked by a notaire. A UK will may contain a choice-of-law clause that requires careful drafting and evidence of the person’s habitual residence and nationality. Separate documents can create contradictions about the same bank account, shareholding or life-insurance beneficiary. Keep signed originals, certified copies, translations and a simple schedule showing which instrument governs which asset.

French forced-heirship rules also need a direct review. The Code civil calls the protected portion the réserve héréditaire, meaning the part of the estate that the law protects for certain heirs, and calls the freely disposable portion the quotité disponible. Article 912 states: “La réserve héréditaire est la part des biens et droits successoraux dont la loi assure la dévolution libre de charges à certains héritiers dits réservataires, s’ils sont appelés à la succession et s’ils l’acceptent.” Read the full Article 912 section of the Code civil on Légifrance.

Article 913 then sets the ordinary limits for gifts and testamentary dispositions: “Les libéralités, soit par actes entre vifs, soit par testament, ne pourront excéder la moitié des biens du disposant, s’il ne laisse à son décès qu’un enfant ; le tiers, s’il laisse deux enfants ; le quart, s’il en laisse trois ou un plus grand nombre.” The current Article 913 text on Légifrance also contains conditions concerning certain international situations. Brexit does not allow a family to ignore the reserve analysis, but neither does it provide a simple answer: the applicable law, the person’s nationality, habitual residence, the will and the timing must be checked together.

Article 724 of the Code civil explains the legal position of heirs: “Les héritiers désignés par la loi sont saisis de plein droit des biens, droits et actions du défunt.” The Article 724 text on Légifrance helps distinguish the heir’s legal title from the practical work of an executor, administrator or notaire. That distinction becomes important when a UK institution asks for probate documents, a French bank asks for an acte de notoriété, or the tax office asks who has authority to sign a declaration. One person may be heir, another may be executor, and a third may be the professional handling the French file.

Family exemptions should be tested rather than assumed. Article 796-0 bis of the General Tax Code provides an exemption for the surviving spouse or surviving civil partner in the circumstances defined by the law. The official Article 796-0 bis text on Légifrance should be read with the legal status of the couple at the date of death. A British civil partnership, marriage or divorce may require recognition documents, certified translations or a determination of its French effect. A beneficiary’s exemption is a French inheritance-tax question; it does not necessarily remove a UK IHT filing obligation or a UK charge on a particular asset.

Valuation is the next pressure point. A French house should have a defensible open-market value at the date of death, expressed in euros for the French declaration and reconciled with any UK sterling calculation. Shares should be valued under the correct market or private-company method. A loan, trust interest, pension, life-insurance contract and jointly held account need a statement explaining what passed at death and what did not. Record exchange rates, valuation reports, professional fees, debts and the reason an item was included or excluded. If the tax offices receive different values, the family should explain the difference rather than submit two unexplained totals.

The French filing deadline is also date-sensitive. Article 641 of the General Tax Code states: “Les délais … De six mois … décès en France métropolitaine; D’une année, dans tous les autres cas.” The Article 641 text on Légifrance sets the statutory framework for the declaration period. A death in France and a death outside metropolitan France can therefore produce different deadlines. The UK IHT filing and payment timetable must be placed beside the French deadline in one calendar, with time reserved for valuations, translations, bank certificates and treaty-clearance requests.

One useful document is a “death-day pack”. It should contain the two current wills, identity and civil-status records, the residence-year schedule, both tax-residence certificates if available, property deeds, investment statements, life-insurance contracts, pension statements, loan agreements, business valuations, gifts made in the relevant period, and the contact details of UK and French professionals. Store it securely and tell the person who will need to find it. A cross-border estate becomes much more expensive when the family learns about a UK account or a French policy only after the first tax declaration has been filed.

Disputes over value are evidence disputes. In Cass. com., 11 January 2017, no. 15-16.454, the Court of Cassation considered a challenge concerning the valuation of inherited property and the evidence needed to establish an error. The case is a reminder that an assertion that a tax value is “too high” should be accompanied by comparable sales, an expert report, defects, occupancy information, title restrictions or another contemporaneous document. A later estate-agent estimate, prepared only after the tax dispute begins, may be less persuasive than evidence made at or close to the death date.

B. What to do if HMRC or the French tax office claims tax twice

When both administrations appear to tax the same estate, pause the instinct to argue only from nationality. Build a table with one row per asset and these columns: asset description, owner, date-of-death value, country of situs, UK treatment, French treatment, tax paid, treaty rule, domestic credit and evidence. Add a second table for the person: UK tax years, French tax years, move date, death date, residence documents and any period of uncertainty. This converts a general complaint about double taxation into a set of questions that HMRC, the French tax office and the professionals can answer.

First, obtain the formal assessments. Ask HMRC for the calculation showing why the estate is within IHT, how the long-term UK residence test was applied and which assets were treated as non-UK property. Ask the French office or the notaire for the French declaration and calculation, including the provision used to tax each category of asset. Do not rely on an informal telephone explanation when the estate needs a refund or treaty claim. Keep the reference number, date, name of the office and every attachment.

Secondly, verify the residence window. The ten-year rule is not established by a passport, a French residence card or a statement that the person “retired to France”. Reconcile the UK tax years with HMRC records and the travel history. Check whether the person was UK resident for one or more of the previous 20 tax years, whether split-year treatment applies, and whether the post-departure tail was still running on the death date. If a year is uncertain, identify the evidence required to resolve it rather than silently excluding it.

Thirdly, verify the situs. For land, start with the physical location. For shares, accounts, insurance, pensions, trusts and partnership interests, apply the relevant UK and French rules and the succession convention. A French property can be relevant to both administrations but may not be treated identically in both calculations. A UK bank account can have a different result from UK land. The classification should be stated asset by asset in the file and supported by the contract, title, statement or governing instrument.

Fourthly, separate allocation from credit. The treaty may assign an asset to one country, or it may allow one country to grant relief for tax charged by the other. Article 784 A can provide a French domestic credit, but its ceiling and the category of property matter. The UK manual explains that the France–UK convention can involve a French return or certificate and different forms according to which country is claiming relief. A tax payment does not automatically generate a credit: the estate normally has to make the correct application, within the applicable time limit, with proof of the foreign tax and the asset to which it relates.

Fifthly, protect the filing deadlines. The French six-month or one-year framework in Article 641 and the applicable UK IHT deadlines continue while the treaty position is being examined. If the full amount cannot be calculated in time, obtain professional advice on an interim declaration, payment on account, amendment or protective claim. Missing a deadline in the hope that the other administration will solve the conflict can create interest, penalties or a limitation problem. Record any request for an extension and the administration’s written response.

Sixthly, make the treaty claim expressly. Identify the article of the convention, the asset, the tax charged in each country, the calculation of the credit or waiver, the payment date and the requested outcome. Attach the death certificate, will, asset valuation, residence evidence, tax assessments, proof of payment and translations. If the claim is for French relief on UK tax, check whether Form 2740 or another form is required in the case. If the claim is for the UK side, ask HMRC what French assessment or certificate it needs. The form number is less important than matching the form to the direction of the relief and the date of the death.

Seventhly, challenge a factual error through the correct channel. An incorrect residence year, missing debt, wrong valuation, mistaken family relationship or failure to apply a treaty credit should be identified in a written correction request or statutory claim. A complaint to a bank will not change the tax assessment. A French inheritance declaration cannot by itself amend a UK IHT determination. Where the disagreement concerns the convention’s application in both countries, the mutual-agreement or competent-authority route may need to be considered, but it should not replace a domestic appeal or refund claim whose deadline is running.

Eighthly, preserve the cash-flow evidence. Keep proof of UK IHT paid, French duties paid, instalments, securities, refunds, interest and any clearance certificate. A credit calculated from a tax assessment that was later reduced may need to be corrected. Conversely, a refund received in one country may affect the relief claimed in the other. Tell both professionals about every adjustment and keep a dated reconciliation. This is particularly important where a family sells an asset to fund the tax and the sale creates a separate income-tax or capital-gains question.

Professional roles should be coordinated. A UK probate lawyer may control the grant and HMRC correspondence. A French notaire may handle the French declaration and civil succession. A tax adviser may calculate the UK LTR window, the treaty credit and foreign-exchange conversions. A family should ask who is responsible for each deliverable and obtain written confirmation that the France–UK succession convention has been considered. No professional should assume that another has filed a claim merely because the estate was discussed at a meeting.

Consider a simple illustration. A British person dies in France while still within the UK long-term-residence tail. The estate includes a French house, UK shares and a French bank account. The UK calculation may examine the worldwide assets because of the LTR status; the French calculation may begin with the deceased’s French tax domicile and Article 750 ter; and the convention may allocate or relieve tax according to residence and situs. The result cannot be obtained by adding the two headline rates. The estate must calculate the tax on each share, apply exemptions and allowances, then make the treaty or domestic credit claim supported by the assessments.

French tax rates provide another reason to avoid a headline-only answer. Article 777 uses different tables depending on the relationship and net share. Article 779 supplies allowances in the situations set out by the statute, while Article 796-0 bis may exempt a surviving spouse or civil partner. The UK nil-rate band and residence nil-rate band have their own conditions. A surviving spouse may receive an exemption in one country while the estate still needs an IHT account in the other. “No tax payable” and “no filing required” are not interchangeable conclusions.

The best time to obtain a cross-border review is before a death or before the first declaration is submitted. The review should produce a residence-year calculation, an asset-situs map, a will and civil-law analysis, a tax estimate for both countries, a treaty-relief plan, a deadline calendar and a document checklist. If a death has already occurred, the same work should begin immediately with the date-of-death documents and the statutory deadlines at the top of the file.

Conclusion

A British resident in France can still face UK Inheritance Tax after Brexit. From 6 April 2025, the long-term UK residence test and its post-departure tail can bring overseas assets into the UK analysis even when the person’s home and tax residence are in France. French domestic rules can also apply, but the France–UK succession convention and the French credit mechanism may prevent an unreduced double charge when the estate makes the correct claim.

The reliable route is not to choose between “British” and “French” as a single answer. Count the UK tax years, determine the death-date tail, classify every asset, apply the relevant French residence and succession provisions, separate civil succession from tax, and keep proof of each payment. The will, residence schedule, valuation file and treaty forms should be prepared as one coordinated estate file, with a separate person responsible for each UK and French deadline.

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