Succession Planning for Multi-Jurisdiction Families: A Practical Guide

International families — where parents hold multiple citizenships, children were born in different countries, assets are held across jurisdictions, and family members may reside on different continents — face a level of complexity in estate and succession planning that domestic families simply do not encounter.

The stakes are high. Without coordinated planning, a family's wealth can be subject to inheritance tax in multiple jurisdictions simultaneously, assets may be frozen pending probate in countries that do not recognise foreign grant of administration, and the distribution of the estate may be determined by laws of forced heirship that conflict with the deceased's intentions.

This guide sets out the key considerations for HNW families navigating multi-jurisdictional succession.

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The Interaction of Citizenship, Domicile, and Residence in Succession

Three legal concepts determine which jurisdiction's succession laws apply to an estate:

Domicile — in common law jurisdictions (UK, Ireland, Australia, Canada, New Zealand, most of the Commonwealth), the key connecting factor for succession to moveable assets (bank accounts, shares, intellectual property) is typically the domicile of the deceased at death. Domicile is a deeply technical concept: you have a domicile of origin (your father's domicile at your birth, under English law) and a domicile of choice (established by residing in a country with the intention of making it your permanent home). Note that for UK inheritance tax purposes the domicile-based connecting factor — including the old "deemed domicile after 15 of 20 years" rule — was abolished from 6 April 2025 and replaced by a residence-based test (see below); domicile under the general law remains relevant to succession (which law governs the estate) even though it no longer drives UK IHT. Changing domicile is harder than changing residence.

Residence/Habitual Residence — in civil law jurisdictions (France, Spain, Italy, Germany, most of continental Europe), and under the EU Succession Regulation, habitual residence is the primary connecting factor. Where you were habitually resident at death generally determines which law governs your estate (subject to EU nationality-based elections, discussed below).

Citizenship/Nationality — in many civil law countries and in the USA, citizenship plays a role in succession rules. Some countries apply the law of the deceased's nationality to moveable property (the lex patriae principle). The US federal estate tax applies to US citizens on their worldwide estate regardless of domicile or residence.

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The EU Succession Regulation (Brussels IV)

The EU Succession Regulation (EU 650/2012), known as Brussels IV, harmonised succession rules across EU member states (excluding Denmark, Ireland, and the UK) from August 2015 onwards. Its core rule is that succession is governed by the law of the member state where the deceased was habitually resident at death.

This is a significant shift from nationality-based rules that previously applied in several EU countries.

Key provision — the nationality election: Brussels IV allows a person to elect that the law of their nationality (citizenship) governs their estate, rather than the law of habitual residence. This election is made in a Will. The election must specify a single nationality; if you hold multiple citizenships, you may elect the law of any one of them.

Why does the election matter? Different succession laws have very different rules on:

• Forced heirship — the mandatory allocation of a minimum share of the estate to certain heirs (typically children or spouses). French réserve héréditaire, Italian legittima, Spanish legítima, and German Pflichtteil are all forms of forced heirship. A person of British nationality resident in France who elects UK law can in principle avoid French forced heirship rules.
• Freedom of testation — common law jurisdictions (UK, Ireland, Australia, etc.) generally allow much greater freedom to leave assets as you choose, subject to claims under family provision legislation
• Capacity and formalities — different countries have different requirements for valid Wills

The Brussels IV election is a powerful tool for internationally mobile individuals, but it must be made carefully and in conjunction with specialist private international law advice.

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Forced Heirship: The Core Risk

Forced heirship is the most significant estate planning constraint for families with assets or residence in civil law jurisdictions. Forced heirship rules reserve a minimum share of the estate for specified heirs (usually children, and sometimes spouses):

France: Children are entitled to a reserved share (réserve héréditaire): one child = 1/2 the estate; two children = 2/3; three or more children = 3/4. A surviving spouse is entitled to one quarter. Lifetime gifts can be brought back for the purpose of calculating whether the réserve has been respected (rapport).

Spain: Two thirds of the Spanish estate are subject to forced heirship. One third must be divided equally among children; a second third can be allocated to children in any proportion (but not away from them entirely).

Italy: Children and spouses have reserved shares, calibrated to the number of surviving heirs.

Germany: A disinherited forced heir can claim the Pflichtteil — half the statutory share they would have received if intestate. Crucially, German Pflichtteil is a monetary claim against the estate, not a right to assets in specie.

For families with real estate in France, Spain, or Italy, even if Brussels IV allows an election to UK law for moveable assets, the lex situs rule means that the law of the country where the property is situated governs succession to immoveable property (land and buildings). French property is governed by French succession law. Brussels IV did not change this.

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US Estate Tax: The Worldwide Reach

For families with US citizens, the US federal estate tax applies on the worldwide estate at death, at rates up to 40%, above the exemption threshold ($15 million per individual for 2026). The One Big Beautiful Bill Act, signed in July 2025, made this higher exemption permanent and indexed to inflation from 2027 — removing the previously scheduled TCJA "sunset" that would have cut the exemption to roughly $7 million.

For non-US persons (non-resident aliens): US estate tax applies to US-situs assets only: US real estate, shares in US corporations, certain US debt instruments, and other US assets. The exemption is only $60,000 for non-resident aliens, creating a significant exposure on US equity portfolios.

UK-US Estate Tax Treaty: The UK-US Double Tax Convention on estate and gift taxes provides credits and mechanisms to avoid double taxation for families with UK and US connections. However, the interaction between UK IHT (which is based on domicile) and US estate tax (which is based on citizenship for citizens) creates complex planning challenges that require specialist treaty advice.

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UK Inheritance Tax and the Domicile Tail

UK inheritance tax (IHT) at 40% applies above the available allowances. From 6 April 2025 the long-standing domicile basis for IHT was replaced by a residence-based system: an individual's worldwide estate is within the IHT net once they are a "long-term UK resident" (broadly, UK-resident in at least 10 of the previous 20 tax years), while those who are not long-term UK residents are exposed only on UK-situs assets. The IHT threshold (the nil-rate band) is £325,000 per individual (frozen to April 2031), with a residence nil-rate band (RNRB) of £175,000 for qualifying residential property passing to direct descendants.

The long-term residence test: The new long-term resident (LTR) test replaced the old "deemed domicile after 15 of 20 years" rule entirely from 6 April 2025. Long-term resident status also has a "tail": a departing former long-term resident can remain within the worldwide IHT net for a number of further tax years (between three and ten, scaling with how long they were UK-resident) after leaving.

Offshore trusts: Assets held in offshore trusts are no longer automatically excluded from IHT for settlors who are long-term UK residents. These changes represent a significant shift for internationally mobile families with UK connections and require updated planning.

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Will Strategy for Multi-Jurisdiction Families

Most specialist estate planners recommend that internationally mobile individuals with significant assets in multiple jurisdictions maintain multiple Wills, each governing assets in a specific jurisdiction.

Benefits of multiple Wills:

• Avoids the practical problems of obtaining a foreign grant of representation by relying on a Will that does not meet local formal requirements
• Allows each Will to be drafted under the law of the relevant jurisdiction
• Reduces delays in administering assets in each country

Key risks:

• Multiple Wills can inadvertently revoke each other if not carefully drafted — each Will should specify its geographic scope and include a non-revocation clause for other Wills
• Conflicts between Wills governing the same assets must be anticipated and resolved

A Brussels IV nationality election (if any) should be consistent across all European Wills.

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Trust Planning

For internationally mobile HNW families, offshore trusts (typically settled in Jersey, Guernsey, Cayman Islands, BVI, or similar jurisdictions) can be an effective mechanism for:

• Holding assets outside the taxable estate of any individual family member
• Providing flexible, multi-generational distribution of wealth
• Separating legal ownership from beneficial enjoyment to facilitate succession

However, trust planning for multi-jurisdiction families is complex:

• US citizen or resident beneficiaries trigger complex PFIC, GILTI, and subpart F reporting obligations
• Settlors who are long-term UK residents may have the trust assets included in their IHT estate following the post-2025 reforms
• Forced heirship jurisdictions may challenge trust structures as attempts to circumvent reserved shares (French courts have taken a restrictive view on this)

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How Global Investments Can Help

Succession planning for multi-jurisdiction families requires a team approach: UK lawyers, international tax advisers, and specialists in the civil law jurisdictions where family members reside or hold property. Our advisers assist with:

• Reviewing the succession law exposures across all relevant jurisdictions
• Coordinating with specialist private international law and estate planning counsel
• Assessing the impact of UK IHT reforms on existing offshore structures
• Reviewing multi-jurisdiction Will strategies to eliminate conflicting provisions
• Advising on trust planning in the context of the post-2025 UK IHT framework

Estate planning should be reviewed at every major life change — a new citizenship, a new country of residence, a significant asset acquisition — and not treated as a one-off exercise. Contact us to ensure your family's succession planning is kept current.

This guide is for general information only and reflects the position as of 2026. Estate and succession law is complex and differs significantly between jurisdictions; this guide cannot cover all variations. Always take specialist legal and tax advice. Global Investments does not provide legal, tax, or estate planning advice.