Succession Planning for Mixed-Nationality Couples in the UK

Succession planning is a crucial consideration for mixed-nationality couples residing in the UK, given the complexities of international estate planning. With assets potentially spanning multiple countries and differing rules on domicile, taxation, and inheritance, navigating cross-border inheritance rules requires careful thought and specialist advice.

Under UK law, transfers between spouses and civil partners are normally exempt from inheritance tax (IHT). However, this exemption is limited when a UK-domiciled individual transfers assets to a non-UK-domiciled spouse or civil partner — in that situation, the exempt amount is capped at the nil rate band (currently £325,000), unless the non-domiciled spouse elects to be treated as UK-domiciled for IHT purposes. We will explore these intricacies and provide clarity on protecting your family’s assets.

Key Takeaways

• Understand how the spouse exemption for IHT is limited when one spouse is non-UK-domiciled, and the options available to address this.
• Recognise the importance of international estate planning in managing cross-border assets effectively.
• Identify strategies — including lifetime trusts, Wills, and domicile elections — for protecting family assets in complex succession planning scenarios.
• Consider the tax implications of transferring assets between spouses or civil partners with different domicile statuses.
• Explore how domicile (not just residency or nationality) determines your IHT liabilities and which spouse exemptions apply.

Understanding Mixed-Nationality Couples

As the number of mixed-nationality couples in the UK grows, so does the need for tailored estate planning advice. These couples face a unique set of challenges when it comes to managing their assets and planning for the future — challenges that go well beyond what a standard UK-only estate plan addresses.

Definition and Significance

Mixed-nationality couples are those where one spouse holds UK citizenship (or is UK-domiciled) and the other holds citizenship of a different country or is domiciled elsewhere. This mix of nationalities — and more importantly, domiciles — can complicate estate planning due to differences in legal systems, tax regulations, and forced heirship rules. Cross-border inheritance rules come into play when assets are located in different countries, when spouses have different domicile statuses, or when the couple’s country of residence differs from their country of domicile.

The significance of understanding these complexities cannot be overstated. In the UK, IHT is charged at 40% on the taxable estate above the nil rate band (£325,000 per person, frozen since 6 April 2009 and confirmed frozen until at least April 2031). For a mixed-nationality couple where one spouse is non-UK-domiciled, the unlimited spouse exemption does not apply — meaning assets passing from the UK-domiciled spouse to the non-domiciled spouse are only exempt up to £325,000, with the excess potentially taxable at 40%. Getting this wrong can result in an enormous and entirely avoidable tax bill.

Demographics of Mixed-Nationality Couples

Mixed-nationality families face significant planning complications, particularly where one spouse has connections to a country with citizenship-based taxation (such as the US) or a country with forced heirship rules (such as France, Spain, or many Middle Eastern nations). When such couples live and work in the UK, they may be subject to multiple countries’ tax rules simultaneously, complicating both their financial and estate planning. For more information on the implications of inheritance tax in the UK, couples can refer to resources like Inheritance Tax Limit in the UK.

Understanding the demographics and the specific challenges faced by mixed-nationality couples is essential for providing them with the right guidance. By acknowledging the intricacies of dual citizenship inheritance laws and the impact of cross-border assets, we can better serve these families in their estate planning needs. In particular, the distinction between residency, nationality, and domicile — and how each affects IHT liability — is something every mixed-nationality couple living in the UK needs to grasp early on. The nil rate band has not increased with inflation since 2009, meaning that ordinary homeowners — not just the wealthy — are increasingly caught by IHT, and this problem is compounded for mixed-nationality couples who cannot rely on the unlimited spouse exemption.

Legal Framework Governing Inheritance

Understanding the legal framework governing inheritance is essential for couples with different nationalities living in the UK. The complexities of inheritance laws can significantly impact how assets are distributed upon death, making it crucial for mixed-nationality couples to be well-informed about both UK rules and the rules of any other relevant jurisdictions.

UK Inheritance Laws

England and Wales have their own set of inheritance laws that dictate how assets are distributed after an individual’s death. A key feature of English law is testamentary freedom — the principle that individuals can leave their assets to whoever they wish through a Will. This contrasts sharply with many civil law jurisdictions (such as France, Germany, or Spain) where forced heirship rules reserve a fixed proportion of the estate for children or close relatives.

However, testamentary freedom in England and Wales is not absolute. The Inheritance (Provision for Family and Dependants) Act 1975 allows certain categories of people — including spouses, civil partners, children, and dependants — to make a claim against the estate if they believe reasonable financial provision has not been made for them.

A critical consideration is UK inheritance tax. IHT is charged at 40% on the value of the estate above the nil rate band (£325,000 per person). A reduced rate of 36% applies if 10% or more of the net estate is left to charity. There is also the residence nil rate band (RNRB) of £175,000 per person, available when a qualifying residential interest passes to direct descendants (children, grandchildren, or step-children — but not nephews, nieces, siblings, friends, or charities). Both the NRB and RNRB are frozen until at least April 2031. The RNRB also tapers away by £1 for every £2 the estate value exceeds £2,000,000. For a married couple where both spouses are UK-domiciled, unused nil rate bands are transferable, meaning up to £1,000,000 (£650,000 combined NRB plus £350,000 combined RNRB) can potentially pass free of IHT. For mixed-nationality couples where one spouse is non-UK-domiciled, the position is far more complicated, and specialist advice is essential.

International Considerations

For mixed-nationality couples, international considerations play a significant role in inheritance planning. One of the fundamental differences between legal systems is how death taxes are collected. In the UK, IHT is an estate tax — it is paid by the personal representatives (executors or administrators) out of the estate before assets are distributed. In contrast, many civil law countries operate inheritance taxation systems, where the heirs themselves are taxed on what they receive.

Understanding these differences is crucial for effective inheritance planning. The UK has double taxation treaties covering IHT with a limited number of countries (including the US, France, Ireland, Italy, India, the Netherlands, Pakistan, South Africa, Sweden, and Switzerland) that can help prevent the same assets being taxed twice. Where no treaty exists, unilateral relief may be available — HMRC will generally give credit for foreign tax paid on the same assets — but this must be carefully assessed. Mixed-nationality couples must consider the laws of both their countries of residence and domicile to ensure their wishes are respected and their estate is managed tax-efficiently.

The Importance of Writing a Will

For mixed-nationality couples, having a Will is not just a legal formality, but a crucial step in securing their spouse’s inheritance rights. When couples have different nationalities and potentially different domicile statuses, the complexity of their estate planning increases significantly due to varying legal requirements and tax implications across different jurisdictions.

Protecting Your Spouse’s Inheritance Rights

Having a Will ensures that your spouse is protected and provided for according to your wishes. Without a Will, the distribution of your estate will be governed by the intestacy rules of England and Wales — and these rules were not designed with mixed-nationality couples in mind.

Under the intestacy rules, a surviving spouse receives the first £322,000 of the estate (as of 2024) plus personal chattels, with the remainder split between the spouse and any children. However, for mixed-nationality couples, the position is complicated by the fact that the intestacy rules do not take into account assets held overseas, forced heirship rules in other jurisdictions, or the limited spouse exemption that applies when the surviving spouse is non-UK-domiciled. This can lead to unexpected tax bills and potential disputes within the family.

Common Misconceptions About Wills

Many couples believe that they don’t need a Will because they think their assets will automatically pass to their spouse. However, this is not always the case, especially for mixed-nationality couples.

Some common misconceptions include:

• Believing that the laws of one country will automatically apply to all assets worldwide — in reality, immovable property (such as a house) is generally governed by the law of the country where it is situated, while movable property follows domicile.
• Thinking that a Will made in one country is automatically valid and effective in another — while the Wills Act 1963 provides some recognition of foreign Wills in England and Wales, this is not universal, and a separate Will for UK assets is often advisable to avoid delays and complications.
• Assuming that without a Will, their spouse will automatically inherit everything — under English intestacy rules, assets above the statutory threshold are shared between the spouse and children, and IHT complications can arise where the spouse is non-UK-domiciled.
• Believing that jointly owned property always passes to the surviving spouse — this depends on whether the property is held as joint tenants (where it passes automatically by survivorship) or as tenants in common (where the deceased’s share forms part of their estate and passes under their Will or the intestacy rules).

To avoid such misconceptions, it’s crucial to seek professional advice tailored to your specific situation.

Expatriate Will Guidelines

For expatriate couples, creating a Will involves additional considerations, such as understanding the tax implications in both the country of residence and any country where assets are held or where a domicile connection exists.

By understanding these guidelines and having a clear, legally binding Will (or Wills), mixed-nationality couples can ensure that their wishes are respected and their loved ones are protected. A Will should be complemented by other planning tools — such as lifetime trusts and Lasting Powers of Attorney (LPAs) — to create a comprehensive estate plan. It’s worth remembering that a Will only takes effect on death, and during probate the entire estate (including sole-name bank accounts, property, and investments) is frozen until a Grant of Probate or Letters of Administration is issued. Lifetime trusts, by contrast, allow trustees to act immediately.

Tax Implications for Mixed-Nationality Couples

The tax landscape for mixed-nationality couples in the UK is complex and multifaceted. As we navigate the intricacies of inheritance tax and cross-border taxation issues, it’s essential to understand how these factors can impact your financial planning and potentially lead to inheritance disputes in mixed nationality families.

Inheritance Tax in the UK

In the UK, inheritance tax is a significant consideration for couples, particularly those with mixed nationalities. Where both spouses are UK-domiciled, the spouse exemption for IHT is unlimited — meaning any amount can pass between them free of IHT. However, where the deceased spouse is UK-domiciled and the surviving spouse is non-UK-domiciled, the spouse exemption is capped at the nil rate band (currently £325,000). Anything above this amount passing to the non-domiciled spouse is subject to IHT at 40%.

This is a significant trap for mixed-nationality couples. For example, if a UK-domiciled husband dies with an estate of £800,000 and leaves everything to his non-UK-domiciled wife, only £325,000 is exempt under the limited spouse exemption. The remaining £475,000 is taxed at 40%, creating a tax bill of £190,000 — even though between two UK-domiciled spouses, the entire amount would have passed tax-free. That £190,000 is money that could have supported the surviving spouse and children for years.

To address this, the non-UK-domiciled spouse can make an election to be treated as UK-domiciled for IHT purposes. This unlocks the unlimited spouse exemption, but it also means that spouse’s worldwide assets become subject to UK IHT — a trade-off that requires very careful analysis of the specific circumstances. The election can be made during the lifetime of both spouses or within two years of the UK-domiciled spouse’s death. It is not a decision to be taken lightly, and the consequences will depend on the value and location of the non-domiciled spouse’s worldwide assets. In some cases, the election saves the family a substantial sum; in others, it could actually increase the total tax liability across jurisdictions.

Cross-Border Taxation Issues

Cross-border taxation issues arise when assets are located in different countries or when spouses have different domicile statuses. This can lead to double taxation, where the same assets are taxed in two different jurisdictions. For mixed-nationality couples, understanding whether a double taxation treaty exists between the UK and the other relevant country is vital to avoid or minimise double taxation.

• Identify all countries where assets are held and understand their respective inheritance or estate tax rules — some countries (such as Australia, Canada, and New Zealand) have no inheritance tax at all, while others have rates that vary depending on the relationship between the deceased and the beneficiary.
• Check whether a double taxation treaty exists between the UK and each relevant country — the UK has IHT treaties with only a limited number of countries, and each treaty operates differently.
• Determine the domicile status of both spouses, as this is the primary connecting factor for UK IHT (not residency or nationality). Remember that deemed domicile rules can apply after 15 out of the previous 20 tax years of UK residence.
• Consider planning strategies such as the non-domiciled spouse election, lifetime trusts, the use of exemptions and reliefs (including the annual gift exemption of £3,000, normal expenditure out of income, and potentially exempt transfers), and coordinated Will planning to minimise overall tax liabilities across jurisdictions.

By carefully considering these factors and seeking specialist advice from a solicitor experienced in cross-border estate planning, mixed-nationality couples can navigate the complexities of inheritance tax and cross-border taxation, ensuring that their estate is planned effectively to benefit their heirs and minimise potential disputes. As Mike Pugh says, “The law — like medicine — is broad. You wouldn’t want your GP doing surgery.” Cross-border IHT planning is a specialist area, and the cost of not getting specialist advice is almost always far greater than the cost of getting it.

Residency and Domicile Considerations

Residency and domicile are two critical — but very different — factors that can significantly impact the estate planning process for mixed-nationality couples residing in the UK. Many people confuse these concepts, but understanding the distinction is essential for navigating the complexities of international estate planning and ensuring that your estate is managed according to your wishes.

What Constitutes Residency?

Residency is typically determined by where you live for a significant part of the year. In the UK, the Statutory Residence Test (SRT) is used to determine an individual’s residency status for tax purposes. The SRT considers various factors, including the number of days spent in the UK, whether you have a home here, and your connections to the UK (such as family, work, and accommodation).

For mixed-nationality couples, understanding residency is important for income tax and capital gains tax purposes. However — and this is a crucial point — UK inheritance tax is based on domicile, not residency. You can be tax-resident in the UK for income tax purposes but non-UK-domiciled for IHT purposes, and vice versa. This distinction is fundamental to estate planning for mixed-nationality couples and is frequently misunderstood, sometimes with devastating financial consequences.

Domicile and Its Impact on Inheritance

Domicile is a more complex concept than residency and is not simply determined by where you live. There are three types of domicile under English law: domicile of origin (acquired at birth, typically your father’s domicile), domicile of dependency (which applies to children under 16), and domicile of choice (acquired by living in a country with the intention of remaining there permanently or indefinitely). Domicile plays the central role in determining which country’s IHT rules apply to your estate.

For mixed-nationality couples, domicile has profound implications for cross-border inheritance rules. If you are considered UK-domiciled, your worldwide assets are subject to UK IHT at 40% above the nil rate band. If you are non-UK-domiciled, only your UK-situated assets (known as UK situs assets) are within the scope of UK IHT. This means a non-UK-domiciled spouse’s overseas bank accounts, foreign property, and foreign investments are outside the UK IHT net — unless they make an election or become deemed domiciled.

There is also the concept of deemed domicile. Under current UK legislation, if you have been UK-resident for at least 15 of the previous 20 tax years, you are treated as UK-domiciled for IHT purposes — regardless of where your actual domicile lies. This is particularly important for the non-UK spouse who may have lived in the UK for many years and may not realise they have become deemed domiciled, thereby bringing their worldwide assets within the scope of UK IHT.

It’s also worth noting that domicile is heavily influenced by intention. For example, even if you have lived in the UK for many years, if you genuinely intend to return to your country of origin permanently, your domicile of choice may remain elsewhere. However, HMRC will look at the evidence of your actions (property ownership, family connections, place of burial, where your children are educated, whether you have renewed or maintained a passport from your country of origin, and so on) rather than simply accepting what you say your intentions are. Domicile disputes with HMRC can be lengthy and expensive, which is why getting professional advice early is so important.

Understanding the distinction between residency and domicile is vital for effective international estate planning. By grasping these concepts, mixed-nationality couples can better navigate the complexities of their estate planning needs and ensure that their wishes are respected — and that they don’t inadvertently trigger a large IHT liability. Plan, don’t panic — but do plan early.

Choosing the Right Jurisdiction

When it comes to estate planning, the question of which jurisdiction’s laws will govern the distribution of your assets is a critical consideration that mixed-nationality couples must carefully address. The jurisdiction governing different categories of assets can significantly impact how your estate is distributed and taxed.

Understanding the implications of jurisdiction is essential, especially for couples with connections to multiple countries. The laws governing inheritance, taxation, and asset distribution vary significantly across jurisdictions, making this a complex area requiring specialist guidance.

Factors Influencing Jurisdiction

Several factors influence which jurisdiction’s laws apply to the estate of a mixed-nationality couple. These include:

• The domicile status of each spouse — this is the primary connecting factor for IHT and for the succession law governing movable property (bank accounts, investments, personal possessions)
• The location of immovable property (real estate) — under English conflict of laws rules, the succession of immovable property is generally governed by the law of the country where the property is situated, regardless of the owner’s domicile
• Any applicable EU regulations (such as Brussels IV / EU Succession Regulation 650/2012, which allows individuals to choose the law of their nationality to govern their succession — though the UK did not adopt Brussels IV, it can still affect UK nationals with property in EU member states)
• Any existing estate planning documents, such as Wills or trust deeds — and whether these have been drafted to deal specifically with the assets in each jurisdiction without inadvertently revoking instruments in other jurisdictions

The choice of jurisdiction can have a profound impact on the estate planning process, affecting everything from the distribution of assets to the IHT liabilities of the estate. For example, if a French national dies domiciled in England owning property in both countries, the English property follows English succession law (testamentary freedom), while the French property may be subject to French forced heirship rules. The IHT position is equally complex — the UK will tax the worldwide estate if the deceased was UK-domiciled, while France may also impose inheritance tax on the French property, requiring careful use of the UK-France double taxation treaty to prevent double taxation.

How to Navigate Different Legal Systems

Navigating different legal systems requires a comprehensive understanding of the laws applicable to the couple’s situation. This includes understanding the implications of dual citizenship on inheritance laws and the spouse’s inheritance rights in each relevant jurisdiction.

For instance, many civil law countries have forced heirship rules that reserve a fixed portion of the estate for children, regardless of the terms of the Will. These rules can conflict directly with the English principle of testamentary freedom. Mixed-nationality couples must consider these differences carefully when planning their estate and may need to work with solicitors in more than one jurisdiction to ensure their planning is effective across borders.

We strongly recommend seeking professional advice to navigate these complexities. A solicitor experienced in cross-border estate planning can provide guidance tailored to the couple’s specific circumstances, ensuring that their estate planning is effective, tax-efficient, and compliant with the laws of all relevant jurisdictions. As Mike Pugh often says, “The law — like medicine — is broad. You wouldn’t want your GP doing surgery.” Cross-border succession planning is a specialist area, and using a specialist can save your family tens or even hundreds of thousands of pounds.

Addressing Cultural Differences

Cultural differences play a significant role in shaping estate planning strategies for mixed-nationality couples residing in the UK. These differences can impact various aspects of estate planning, from the distribution of assets to the care of children and even the structure of the family unit itself.

Communication and Understanding

Effective communication is crucial in navigating the cultural nuances that can affect estate planning decisions. Couples should strive to understand each other’s cultural backgrounds and how these influence their expectations and wishes regarding inheritance.

For instance, some cultures place a strong emphasis on providing for the extended family, with expectations that assets will be shared among a wider group of relatives. Others may prioritise the financial security of the surviving spouse above all else. In some traditions, there are expectations about which assets (particularly the family home or family land) should remain within the bloodline. Understanding these cultural preferences is vital in creating an estate plan that respects both partners’ values while remaining legally effective under English and Welsh law.

Key considerations include:

• Discussing cultural expectations openly and how they impact estate planning decisions — particularly around which family members are expected to benefit and in what proportions.
• Understanding the legal implications of cultural practices on inheritance — for example, forced heirship rules in one spouse’s home country may create obligations that conflict with the couple’s UK-based plan, and some religious inheritance customs (such as Islamic inheritance rules) may not align with English testamentary freedom.
• Seeking professional advice to ensure compliance with UK laws while respecting cultural traditions — a well-drafted Will and trust structure can often accommodate both, using the flexibility that English law provides.

Culturally Specific Inheritance Customs

Culturally specific inheritance customs can significantly influence estate planning. For example, in some cultures, the eldest son is expected to inherit the family home. In others, daughters receive a specific share dictated by religious or customary law. In many Asian and Middle Eastern cultures, there are specific rules about the division of property between male and female heirs.

To address these customs effectively, couples should:

1. Identify culturally specific inheritance practices that are important to them and discuss these openly — it is far better to address potential disagreements during the planning process than to leave them for family members to resolve after a death.
2. Discuss how these practices can be incorporated into their estate plan — English testamentary freedom allows considerable flexibility, but this needs to be balanced against the risk of claims under the Inheritance (Provision for Family and Dependants) Act 1975, which allows spouses, children, and dependants to challenge a Will if they believe reasonable financial provision has not been made for them.
3. Consult with a solicitor who is knowledgeable about cross-cultural estate planning and UK inheritance tax advice — particularly one who understands the interaction between English law and the succession laws of the other relevant jurisdiction, and who can ensure that the plan works across both legal systems.

By doing so, mixed-nationality couples can create an estate plan that not only complies with UK laws but also respects their cultural identities. This approach ensures that their wishes are honoured and their loved ones are protected, in line with expatriate will guidelines and UK inheritance tax advice. Not losing the family money provides the greatest peace of mind above all else — and getting the cultural and legal elements right from the start is the best way to achieve that.

Trusts as an Inheritance Tool

For couples with different nationalities, creating a comprehensive inheritance plan is crucial — and trusts are one of the most powerful tools available under English law. England invented trust law over 800 years ago, and trusts remain a flexible and secure way to manage and distribute assets according to a couple’s wishes, while also addressing potential tax implications and legal complexities across borders.

Overview of Trusts

A trust is a legal arrangement where one party (the settlor) transfers assets to trustees to hold and manage for the benefit of specified individuals (the beneficiaries). Critically, a trust is not a legal entity — it has no separate legal personality. The trustees are the legal owners of the trust property, and they hold it subject to their duties under the trust deed and the general law.

The primary classification of trusts under English law is between lifetime trusts (created during the settlor’s lifetime) and will trusts (created through a Will and taking effect on death). Within these categories, the most common types include discretionary trusts, bare trusts, and interest in possession trusts. Each type serves different purposes and has very different tax and legal consequences. For mixed-nationality couples, discretionary trusts are often the most useful because they give trustees the flexibility to distribute assets among beneficiaries — including a non-UK-domiciled spouse — in the most tax-efficient manner, adapting to changing circumstances over time. No beneficiary has an automatic right to income or capital in a discretionary trust, which is the key protection mechanism — it means assets held in the trust are not treated as belonging to any individual beneficiary for IHT, divorce, or creditor purposes. Learn more about trusts for inheritance tax planning.

Benefits for Mixed-Nationality Couples

Trusts offer several benefits for mixed-nationality couples, particularly in managing assets tax-efficiently and protecting the estate of a foreign spouse in the UK.

Key benefits of trusts for mixed-nationality couples include:

• Managing cross-border tax implications — a properly structured trust can help manage the interaction between UK IHT and foreign inheritance taxes, and may be used to hold assets in a way that reduces the overall tax burden across jurisdictions. For example, a will trust with an interest in possession for the surviving non-UK-domiciled spouse can provide income and security while keeping capital protected for children.
• Protecting assets for beneficiaries — a discretionary trust ensures that no beneficiary has an automatic right to the trust property, providing protection against divorce, bankruptcy, and family disputes. With the UK divorce rate at around 42%, this protection is not theoretical — it is practical. As Mike Pugh puts it: “What house? I don’t own a house.”
• Providing flexibility in distribution — trustees can adapt distributions based on changing circumstances, tax laws, or family needs, which is invaluable when dealing with multiple jurisdictions where the rules may change.
• Bypassing probate delays — trust assets do not form part of the deceased’s probate estate, meaning trustees can act immediately on the settlor’s death without waiting months for a Grant of Probate. This is particularly valuable where the probate process in multiple countries might otherwise cause extensive delays — in England and Wales alone, the full probate process typically takes 3 to 12 months, and longer where property needs to be sold.
• Minimising potential for inheritance disputes — clear trust structures, combined with a letter of wishes, reduce the scope for family disagreements about asset distribution. This is especially important in mixed-nationality families where different cultural expectations about inheritance can create tension.

It’s important to note that trusts are tax-efficient planning tools, not tax avoidance schemes. They must be properly structured and registered with HMRC’s Trust Registration Service (TRS) within 90 days of creation — this is mandatory for all UK express trusts. Discretionary trusts are subject to the relevant property regime, which includes a potential entry charge of 20% on values above the available nil rate band (for most family homes, this is zero), periodic 10-year charges of up to a maximum of 6% (again, often zero for estates below the NRB), and proportional exit charges. By utilising trusts alongside well-drafted Wills, mixed-nationality couples can create a more secure and predictable inheritance plan, addressing the complexities that arise from differing legal and tax systems. Trusts are not just for the rich — they’re for the smart.

Planning for Children from Different Nationalities

For mixed-nationality couples residing in the UK, planning for the future of their children involves navigating multiple legal systems. Ensuring that your children are protected and provided for, regardless of their nationality or domicile, is a crucial aspect of estate planning that requires careful consideration of the laws in all relevant jurisdictions.

Legal Rights of Children

Children from mixed-nationality marriages have specific legal rights that must be considered when planning your estate. In England and Wales, there is no automatic right for children to inherit — the principle of testamentary freedom means a parent can technically leave their entire estate to someone other than their children. However, children (including adult children) can bring a claim under the Inheritance (Provision for Family and Dependants) Act 1975 if they believe reasonable financial provision has not been made for them.

This contrasts sharply with many other jurisdictions. In France, for example, forced heirship rules (known as réserve héréditaire) reserve a fixed portion of the estate for children — one child receives at least half the estate, two children receive at least two-thirds, and three or more children receive at least three-quarters. Similar rules exist in many European, Middle Eastern, and South American countries.

It’s essential to understand these differences to ensure that your children’s rights are protected in all relevant jurisdictions. We recommend consulting with a solicitor who is familiar with both UK law and the laws of your spouse’s country of origin or domicile, particularly where property or other assets are held in that country.

Considerations for Custodianship

When planning for your children’s future, it’s also crucial to consider guardianship arrangements. In the event that both parents pass away while the children are minors, who will care for the children? Appointing a guardian in your Will is a vital decision that should be made with careful thought and legal guidance.

For mixed-nationality couples, guardianship can become especially complex due to differing legal frameworks, cultural expectations, and the potential for the children to hold citizenship of multiple countries. Questions may arise about which country the children should live in, which legal system governs their care, and how their inheritance should be managed during their minority.

It’s advisable to clearly document your wishes regarding guardianship in your Will, taking into account the best interests of your children. A discretionary trust can be an excellent complement to guardianship provisions — it allows you to provide for your children’s financial needs (education, housing, maintenance) while keeping the assets protected and managed by trustees until the children are mature enough to handle their inheritance responsibly. Unlike a bare trust, where a beneficiary gains absolute entitlement at age 18 (and can demand the entire trust fund at that age under the principle in Saunders v Vautier), a discretionary trust gives trustees the flexibility to release capital and income when it is genuinely needed — not simply when the beneficiary reaches a birthday. A discretionary trust can last up to 125 years, providing multi-generational protection that is particularly valuable when children may live in different countries with different legal and tax systems.

For couples with significant cross-border planning needs, coordinating the Will and trust provisions with any equivalent instruments in the other jurisdiction is essential. This requires international estate planning expertise to ensure that provisions in one country do not inadvertently conflict with or revoke provisions in another. It is also important to consider Lasting Powers of Attorney (LPAs) — both for property and financial affairs and for health and welfare — alongside any equivalent instruments required in other jurisdictions, so that your affairs can be managed if you lose capacity during your lifetime.

Seeking Professional Advice

Navigating the complexities of succession planning for mixed-nationality couples requires expert guidance, particularly when dealing with cross-border inheritance rules and dual citizenship inheritance laws. We understand the importance of seeking professional advice to ensure that your estate is managed effectively and that you don’t fall into the many traps that catch mixed-nationality families unaware.

Expert Guidance for Complex Issues

Solicitors and legal experts with cross-border experience play a crucial role in helping you understand the intricacies of inheritance laws and tax implications across multiple jurisdictions. They can provide personalised advice on managing your estate, including strategies such as the non-domiciled spouse election (which allows a non-UK-domiciled spouse to elect to be treated as UK-domiciled for IHT purposes, thereby unlocking the unlimited spouse exemption — but with the consequence that their worldwide assets then fall within the scope of UK IHT).

Key areas where specialist advice is essential include:

• Domicile analysis — correctly determining each spouse’s domicile status, including whether deemed domicile rules apply after 15 out of the previous 20 tax years of UK residence, and understanding how domicile of origin can revive when a person leaves a country of choice
• Structuring Wills across jurisdictions — ensuring that Wills in different countries work together without revoking each other, and that each Will deals only with the assets in its intended jurisdiction
• Trust planning — using lifetime trusts and will trusts to manage assets tax-efficiently across borders, taking into account how trusts are treated in both the UK and the other relevant jurisdiction (some civil law countries do not recognise trusts at all, which requires careful structuring)
• Double taxation relief — identifying applicable treaties and claiming relief to prevent the same assets being taxed twice, or using unilateral relief where no treaty exists
• Lasting Powers of Attorney — ensuring that LPAs are in place for both property and financial affairs and health and welfare decisions, alongside any equivalent instruments required in other jurisdictions (such as a mandat de protection future in France or a Vorsorgevollmacht in Germany)

At MP Estate Planning, we help mixed-nationality couples understand their options and put practical plans in place. Mike Pugh’s Estate Pro AI — a proprietary 13-point threat analysis — can identify the specific risks facing your family and help determine which combination of trusts, Wills, and tax planning strategies will work best for your circumstances. For further guidance on inheritance tax planning, explore our resources or get in touch for a consultation. Plan, don’t panic — and above all, don’t leave it to chance when your family’s financial future depends on getting this right. Keeping families wealthy strengthens the country as a whole.