For a British heir dealing with a French estate, the first tax question is rarely the final amount. It is usually more urgent: when must the French inheritance tax return be filed, where must it be sent, and what happens if the property cannot be sold in time? Brexit does not create a general exemption from French succession tax. The decisive facts are the deceased’s place of death, fiscal domicile, the location of the assets, the family relationship, the wording of any will, and the interaction between French rules and the France–UK inheritance tax convention.
In France, the déclaration de succession is the inheritance tax return. The droits de mutation à titre gratuit are the French duties charged on a transfer by death. A British citizen living in England, Scotland, Wales or Northern Ireland may still have to file in France if the estate contains French property or another asset within the French taxing rules. The return is not simply an administrative formality which can wait until the notary has finished every part of the estate. It can trigger payment, interest, penalties and joint liability between heirs.
This guide explains the deadline, the correct French tax office, the documents a UK-based heir should assemble, the instalment and deferred-payment routes, and the evidence needed to challenge an incorrect bill. It also separates the French filing duty from the treaty question: a treaty may reduce double taxation, but it does not give an heir permission to ignore a French filing deadline.
I. What is the French inheritance tax declaration deadline for a British heir?
A. Does France give six months or one year, and who must file?
The starting point is Article 641 of the French General Tax Code (Code général des impôts, or CGI). The official text gives two basic periods: six months from the date of death when the deceased died in metropolitan France, and one year in all other cases. The legal wording is: « Les délais pour l’enregistrement des déclarations que les héritiers, donataires ou légataires ont à souscrire des biens à eux échus ou transmis par décès sont : De six mois, à compter du jour du décès, lorsque celui dont on recueille la succession est décédé en France métropolitaine; D’une année, dans tous les autres cas. » The French text is decisive; a translation is provided here only to make the rule usable for a British reader.
In practical terms, a death in France normally means a six-month filing period. A death in the United Kingdom normally falls within the one-year category, even if the estate contains a French house, French bank account or French shares. The place of death and the deceased’s domicile are separate questions. The place of death helps determine the filing period; the deceased’s residence usually determines which French office receives the return. Do not assume that a British address automatically means that France has no filing jurisdiction, or that a French asset automatically means that the six-month period applies.
The official English guidance from Service-Public.fr confirms that the return is due within six months for metropolitan France and within twelve months when the deceased died abroad. It also states that the estate tax is payable when the return is filed. That combination matters. The deadline is not merely a deadline for sending information; it is normally the point at which the French administration expects the duties to be paid or a lawful credit arrangement to be requested.
Who must file? Article 800 CGI states that heirs, legatees and donees, together with their tutors or curators where relevant, must submit a detailed declaration. It provides limited exemptions based on the gross value of the estate and the relationship to the deceased. For example, a child, surviving spouse or civil-partnership partner may be exempt where the gross estate is below €50,000 and the other statutory conditions are met; other beneficiaries may be exempt below €3,000. British nationality, residence in the UK and the fact that the heir has not yet received cash are not exemptions by themselves.
If there are several heirs, a single declaration may often be prepared for the estate, but that does not mean that each heir can leave the matter to somebody else without risk. Article 1709 CGI provides that the co-heirs, except those exempt from inheritance duties, are jointly liable. In plain English, the French tax authority may pursue the whole amount from one heir, leaving that heir to seek contribution from the others. This is especially important for a British heir who signs nothing, assumes that a French sibling will deal with the tax, and later receives a demand for the unpaid balance.
The civil-law concept of legal possession also explains why a disagreement about the estate does not necessarily suspend the tax work. Article 724 of the French Civil Code says: « Les héritiers désignés par la loi sont saisis de plein droit des biens, droits et actions du défunt. » This means that heirs designated by law are treated as taking the deceased’s assets, rights and claims automatically, subject to the detailed succession rules.
The Cour de cassation applied that combination in its commercial chamber judgment of 8 March 2005, appeal no. 02-12.721. The Court held, in terms verified through Judilibre, that « les héritiers légitimes, qui sont saisis de plein droit des biens, droits et actions du défunt, sont tenus de souscrire une déclaration de succession qui doit être enregistrée dans le délai de six mois à compter du jour du décès, que les droits de mutation par décès sont payés avant l’exécution de l’enregistrement ». The official decision no. 02-12.721 is particularly useful when an heir argues that a dispute inside the family justifies waiting.
A more recent procedural example is the Cour de cassation’s QPC referral of 5 April 2023, appeal no. 23-40.001. The dispute concerned reserved heirs who had not necessarily received the underlying assets. The Court nevertheless recorded that the heir was required to file within six months and pay the transfer duties. Its verified wording states that the heir « est cependant tenu de déposer une déclaration de succession dans les six mois suivant le décès et de s’acquitter des droits de mutation à titre gratuit ». The official decision no. 23-40.001 does not mean that every family dispute produces the same result. It does show why the tax timetable needs its own urgent plan.
For a British family, the first deadline calculation should therefore answer five questions: where did the deceased die; where was the deceased domiciled; what assets were situated in France; which person is legally entitled to the estate; and has a French declaration already been filed? Record the date of death, add the relevant six- or twelve-month period, and work backwards from that date for valuations, documents, translations and any request for instalments. Waiting for a Grant of Probate in England or for an eventual sale of a French property can consume the entire period.
B. Which French tax office and documents does a UK-based heir need?
The filing office depends mainly on where the deceased lived. If the deceased was resident in France, the declaration is normally made to the registration service connected with the deceased’s French home. If the deceased was resident outside France, the return for the French estate is sent to the Recette des non-résidents, the French non-resident tax collection office. The current impots.gouv.fr guidance identifies the non-resident service at 10 rue du Centre, TSA 50014, 93465 Noisy-le-Grand Cedex, and explains that the declaration is filed with the payment.
The English Service-Public page gives the same route for a deceased person living abroad: the return goes to the non-resident personal income tax department. Check the address and payment instructions immediately before sending the papers, because French public-service contact details can change. Keep proof of delivery, a complete copy of every form, the bank transfer reference and any acknowledgement from the tax office. A British heir should not rely on a post-office receipt alone if a large amount is at stake.
Start the file with the death certificate, evidence of the deceased’s last residence, the family record book or equivalent civil-status documents, the will, any codicil, and the French acte de notoriété. An acte de notoriété is the French notarial document identifying the persons entitled to inherit. Where the estate includes French real estate, a French notary will usually be involved because the transfer of land and the property title need to be dealt with under French conveyancing rules. Using a notary does not remove the heir’s exposure to the tax administration. Service-Public expressly notes that an heir may ask a notary to complete the return while remaining responsible to the tax authority.
For the asset schedule, gather title deeds, current and historic valuations, bank statements at the date of death, share registers, insurance policies, pension or annuity statements, details of loans, funeral costs, gifts made during the relevant period, and evidence of debts that were legally deductible. For UK assets, keep the probate inventory, valuations prepared for HMRC, IHT forms where applicable, statements from banks and pension providers, and confirmation of inheritance tax paid in the UK. The French administration needs to understand not only what is in France but also whether a treaty credit or an exclusion is being claimed.
Translate the facts rather than translating blindly. “House in France” is not enough. State whether it is owned outright, jointly owned, held through a company, subject to a mortgage, occupied by a surviving spouse, or divided between usufruit and nue-propriété. Usufruit is the right to use the property or receive its income; nue-propriété is bare ownership without that present use. Explain whether a UK investment is a bank deposit, a company share, a pension right, a trust interest or an insurance policy. The French tax treatment can change with the legal nature of the asset.
Do not treat the France–UK inheritance convention as a substitute for the return. The 1963 France–UK inheritance tax convention, published by French Decree no. 64-789, allocates taxing rights by reference to the deceased’s domicile and the situs of particular assets. The French tax administration also explains that international conventions do not generally remove the declaration rules; they may affect which state taxes an asset and how double taxation is relieved. The treaty is therefore a calculation and evidence issue after the filing obligation has been identified.
In a cross-border file, make a one-page map with four columns: asset, legal owner, country in which it is treated as situated, and evidence of tax paid. Add a fifth column stating whether the item is included in the French declaration, excluded under the convention, or included with a possible foreign-tax credit. That simple map is often more useful than a large bundle of untranslated bank statements.
II. How can a British heir pay, challenge or reduce a French inheritance tax bill?
A. Can you obtain instalments, avoid penalties or deal with an illiquid property?
The ordinary rule is payment when the declaration is registered. Article 1701 CGI states: « Les droits des actes et ceux des mutations par décès sont payés avant l’exécution de l’enregistrement […] Nul ne peut en atténuer ni différer le paiement sous le prétexte de contestation sur la quotité, ni pour quelque autre motif que ce soit, sauf à se pourvoir en restitution s’il y a lieu. » A British heir who disputes the valuation should not assume that the dispute itself suspends payment.
There is, however, a structured credit route. Article 1717 CGI permits the payment of registration duties to be split or deferred under statutory conditions. The French terms are paiement fractionné, meaning instalment payment, and paiement différé, meaning deferred payment. The request should be made with the declaration or at the time the declaration is lodged, not after the estate has already defaulted.
For the ordinary instalment route, the official Service-Public guidance describes up to one year after the end of the filing period, normally with three payments. If at least 50% of the estate consists of biens non liquides, or illiquid assets that cannot be sold quickly, the period can extend to three years with up to seven payments. Examples include French land, art and unlisted securities. The official impots.gouv.fr page confirms the three-year possibility for an estate containing at least 50% illiquid assets.
The application is not automatic. All heirs who remain jointly liable need to be coordinated. The tax office will normally require guarantees, such as a mortgage over property, and interest is payable. Service-Public states that the request must be attached to the declaration, that the tax services should respond within two months, and that the guarantees must be presented within four months if the request is accepted. Put those dates in a calendar. Missing an instalment can cause the whole balance to become immediately payable.
Deferred payment is a different tool. It can be relevant where an heir receives bare ownership while another person holds usufruit, or in certain cases involving a preferential allocation of an agricultural business or a reduction payment owed between heirs. A British heir who inherits a French property subject to a surviving spouse’s life interest should ask the notary and the tax office whether deferred payment applies to the relevant part of the duty. It is not a general right to postpone all inheritance tax until the property is sold.
If the declaration is late, an instalment request does not erase the late-filing consequences. Article 1728 CGI applies a 10% increase in the situations specified by the statute and a 40% increase where the return is not filed within ninety days after the relevant formal notice. The statutory text also links the inheritance-return rule to the expiry of the six-month or special period. The 2019 decision of the Cour de cassation, appeal no. 18-18.915, states in verified terms that failure to respect the period may lead to a 10% increase, while failure to file within ninety days of a formal notice may lead to 40%. Read the official decision no. 18-18.915 before relying on an informal promise that the tax office will wait.
That case concerned a succession involving assets in France and a succession representative who needed liquidity to address both property costs and tax exposure. The Court recorded that the French assets had to be declared and that the anticipated tax debt and penalties could justify a sale needed for the proper administration of the estate. The lesson for a British executor or heir is practical: if cash is unavailable, produce a funding plan early. That plan may include a permitted instalment request, a guarantee, a partial sale, a loan secured on the French property, or an advance between co-heirs. “The property is not yet sold” is not a complete answer to a tax demand.
Joint liability makes the choice of payment method a family decision. A British heir who pays the whole amount can seek reimbursement from the other heirs, but that later civil claim may be expensive, especially when the family lives in different countries. Agree in writing who will fund the first payment, who will provide the guarantee, how interest will be shared, and what happens if the French property sells below the valuation used in the return.
The amount also needs a calculation rather than a guess. Article 777 CGI sets the progressive rates for a taxable share passing in the direct line, together with the rates for siblings, more remote relatives and non-relatives. The relationship to the deceased and available allowances matter more than the heir’s British passport. A surviving spouse or civil-partnership partner may have a different treatment from an adult child, sibling or unmarried partner. Check prior gifts and the applicable allowance before accepting a number supplied by another heir.
B. How do you challenge valuation, double taxation and an incorrect assessment?
A challenge should start by identifying exactly what is wrong. Common grounds include a wrong death date or place, the wrong deceased’s domicile, an asset included in the wrong country, a property value that ignores a legal restriction, a debt rejected without explanation, an incorrect family relationship, a missed allowance, a UK tax credit omitted, or a penalty calculated from the wrong filing period. A British heir should separate a disagreement over the amount from a failure to file. The first can be argued in a complete return; the second can create an avoidable penalty problem.
The territorial rule is central. Article 750 ter CGI can bring French or foreign assets into the French inheritance-tax base where the deceased was fiscally domiciled in France, and it contains separate rules for French-situated assets and for an heir who has been resident in France for at least six of the preceding ten years. That is why a British heir should not decide the French scope from nationality alone. The 2025 commercial chamber decision no. 24-16.995 dealt with a French succession, assets held through structures and the administration’s ability to require a new declaration after the first one had been annulled. The Court stated that the heirs were in a situation of declarative default after the declaration disappeared and that the administration’s procedure had then been validly started. The official decision no. 24-16.995 is a warning to preserve the legal effect of every document filed.
For a UK-resident family, the convention must then be applied asset by asset. The HMRC inheritance tax manual on France explains that, where the deceased was fiscally domiciled in France, the UK may have to give up its taxing right over assets treated as situated in France under the convention. It also describes the use of a French tax certificate when a UK inheritance-tax credit is claimed. The French BOFiP guidance on the France–UK convention explains that a reduction for tax paid in the other country can be available, subject to the treaty and a time limit for the claim. Do not assume that a UK IHT payment automatically produces a French refund; attach the evidence and make the claim in the correct form and period.
Valuation disputes need evidence dated at or close to death. For a French house, assemble an independent appraisal, comparable sales, photographs, planning restrictions, occupancy agreements, repair estimates, usufruit or bare-ownership documents, and any evidence that a sale could not have occurred at the administration’s figure. For shares or a private company, obtain the articles, accounts, transfer restrictions and a defensible valuation method. For a UK bank account, pension or trust interest, identify the legal right held at death rather than simply copying the balance shown months later.
Do not overlook the difference between a tax return and a tax assessment. If the administration has issued a formal demand, preserve the avis de mise en recouvrement, meaning the notice placing the tax into collection, and the full calculation. If it has issued a mise en demeure, meaning a formal notice to file, record the date received and the ninety-day period. A late response may change the penalty exposure. If the administration rejects a written explanation, a réclamation contentieuse is the formal tax claim challenging the assessment or requesting relief; it should be framed around the exact legal and factual errors, not a general statement that the amount feels excessive.
Prescription also needs care. Article L. 180 of the French Tax Procedures Code gives a three-year recovery period for registration duties where the registered document or declaration sufficiently reveals the tax exigibility. Article L. 186 provides a six-year period where no shorter or longer period is expressly provided. The applicable rule depends on what was filed, what was disclosed and how the administration proceeded. A British heir should not calculate a limitation period from the date of a letter without having the complete filing and assessment history reviewed.
The 2025 decision no. 24-16.995 shows why a missing or annulled declaration can alter the administration’s procedural position. The Court’s verified wording refers to the heirs being in “situation de défaillance déclarative” and to a valid procedure following formal notice. That does not authorise the administration to ignore every procedural safeguard. It means that the heir must preserve proof of filing, challenge an invalid notice, and explain any corrected declaration clearly.
If the family dispute concerns the entitlement itself, the 2005 decision no. 02-12.721 remains a useful warning: an action about the surviving spouse’s rights did not allow the heir to postpone the French declaration and payment. If the dispute concerns a universal legatee and a reserved share, decision no. 23-40.001 shows the financial pressure created when a reserved heir owes duties before receiving the corresponding cash. Those cases should be used carefully and factually. They are not a substitute for checking the current statute, the treaty, the exact estate structure and the dates in the individual file.
A sensible challenge sequence is therefore:
First, file or regularise the return before the deadline, stating clearly any provisional valuation or disputed item and attaching an explanatory schedule. Second, pay the undisputed amount or submit a properly supported instalment or deferred-payment request with the required guarantee. Third, notify the French tax office of the treaty position and attach proof of any UK inheritance tax paid or due. Fourth, obtain the calculation behind the bill and compare every asset, debt, allowance, rate and penalty. Fifth, submit the formal claim within the applicable procedural period and keep proof of delivery. Sixth, if the amount, penalty or treaty relief remains disputed, instruct counsel who can handle the French tax procedure and coordinate with the UK executor, solicitor or tax adviser.
That sequence protects the estate from a common mistake: treating a potential argument as permission to do nothing. A strong French tax challenge usually starts with a timely return, a transparent reservation of rights, and evidence that allows the administration to see which part of the bill is contested. It also protects the British heir against being the only family member who understands the risk after the penalties and joint-liability notices have already arrived.
Conclusion
A British heir can face a French inheritance tax filing duty after Brexit even when the heir lives permanently in the UK. The key deadline is generally six months when the deceased died in metropolitan France and twelve months when the death occurred abroad, but the deceased’s residence and the asset location determine the filing office and the French taxing analysis. A return concerning a deceased person who lived outside France normally goes to the French non-resident tax service, with payment or a structured credit request.
The practical priorities are to calculate the deadline from the death certificate, identify the correct office, collect the estate and UK tax evidence, map every asset by legal nature and location, and request instalments or deferred payment at the time of filing if cash is tied up in French property. A treaty credit, a valuation objection or a penalty challenge should be supported by documents and raised through the correct French procedure. Do not wait for a property sale, a family settlement or an informal promise from another heir to protect the estate from a deadline that runs independently.
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