US Estate Tax on UK Assets |

US Estate Tax on UK Assets: A Complete Guide

US Estate Tax on UK Assets for US Citizens Abroad

The US estate tax on UK assets is a subject that most Americans living in Britain have never properly considered. Yet, it can have a dramatic impact on how much of their estate actually passes to their family after they die. Furthermore, the United States taxes the worldwide estate of every US citizen regardless of where they live — a rule that stands in stark contrast to the UK's inheritance tax system, which is primarily based on domicile rather than citizenship. Consequently, a US citizen who has lived in London for twenty years, owns a family home in Surrey, holds a UK pension, and has savings in a UK bank is fully exposed to US federal estate tax on all of those assets, in addition to any UK inheritance tax that may also apply.

Additionally, many UK-resident US citizens believe that a long period of residence in the UK somehow diminishes their exposure to the US estate tax system. Unfortunately, this is not correct — only renouncing US citizenship or dying as a non-resident alien removes a person from the scope of the US estate tax on worldwide assets. Moreover, the interaction between UK inheritance tax and US estate tax creates a genuine risk of double taxation on the same assets unless careful planning is undertaken in advance. Therefore, understanding the rules on both sides of the Atlantic is essential for any US citizen with significant UK assets.

How the US Estate Tax System Works

Worldwide Taxation for US Citizens

The US estate tax on UK assets The US federal estate tax applies at a flat rate of 40% on the value of a deceased US citizen's taxable estate above the applicable exemption amount. Specifically, the current lifetime exemption — unified with the gift tax exemption — stands at $13.61 million per individual for 2024, indexed annually for inflation. Furthermore, married couples can effectively double this exemption through the portability election, allowing unused exemption from the first spouse's death to be transferred to the surviving spouse. Consequently, for estates below these thresholds, the US federal estate tax will not apply, though the return may still need to be filed.

However, a critical legislative risk looms on the horizon. Specifically, the elevated exemption introduced by the Tax Cuts and Jobs Act of 2017 is scheduled to sunset after 31 December 2025, reverting to approximately $7 million per person (inflation-adjusted) unless Congress extends it. Therefore, US citizens with estates between $7 million and $13.61 million who have not undertaken estate planning may be subject to a 40% charge on amounts above the reduced threshold after 2025. Accordingly, 2025 is a particularly important year for estate planning reviews for Americans living in the UK with significant assets.

What Assets Are Included in the US Estate?

The US estate tax on UK assets The US taxable estate of a US citizen includes virtually all assets, wherever situated in the world. Notably, this covers UK residential property — including the family home — UK bank and investment accounts, shares in UK companies, UK pension funds (with important exceptions), life insurance policies, business interests, and any other property in which the deceased had a beneficial interest at the date of death. Furthermore, assets held in certain trusts may also be included depending on the nature of the trust and the powers retained by the settlor.

One area that causes particular confusion is the UK pension. Specifically, defined contribution pension pots that have not been drawn down are generally not included in the US gross estate, because the pension fund is held in trust and the individual does not have an outright legal interest in the assets at death. However, the position is not entirely settled and depends on the specific pension scheme rules, the nature of any nominated dea, and how the IRS characterizes the underlying arrangement. Therefore, pension planning should always be reviewed as part of a comprehensive cross-border estate plan.

UK Inheritance Tax and the Double Tax Risk

How UK IHT Applies to US Citizens in the UK

The US estate tax on UK assets UK inheritance tax applies based on domicile rather than citizenship. Specifically, a person who is UK domiciled — broadly, someone who has made the UK their permanent home and has lived there for a long time with no intention of leaving permanently — is subject to UK IHT on their worldwide assets at 40% above the nil-rate band of £325,000, with an additional residence nil-rate band of £175,000 available where a qualifying residence is left to direct descendants. Furthermore, a person can acquire a deemed domicile in the UK after being a UK resident for fifteen of the previous twenty tax years, which is a lower threshold than many US citizens resident in the UK realize.

Consequently, a US citizen who has lived in the UK for 15 or more years may be both US-domiciled for US estate tax purposes — because the US taxes all its citizens on a worldwide basis regardless of domicile — and deemed UK-domiciled for IHT purposes. This means their worldwide estate is potentially subject to both a 40% US estate tax and a 40% UK IHT charge on the same assets, with both countries asserting taxing rights simultaneously. Moreover, this is precisely the scenario that the US-UK Estate Tax Treaty was designed to address, though its provisions are limited in scope and do not resolve every case.

The US-UK Estate Tax Treaty

The United States and the United Kingdom concluded an estate and gift tax treaty that allocates taxing rights between the two countries based on domicile. Specifically, the treaty provides that where a deceased person was domiciled in one country at the time of death, that country has primary taxing rights on the worldwide estate, while the other country's taxing rights are generally limited to assets situated within its territory. Furthermore, the treaty provides a credit mechanism to prevent double taxation when both countries assert taxing rights over the same asset.

However, the treaty has important limitations. Notably, it applies to domicile in the treaty sense, which is a legal concept that does not always align with either the US citizenship-based estate tax or the UK deemed domicile rules. Additionally, the treaty does not cover all types of assets, and the credit provisions do not always fully eliminate double taxation in practice. Therefore, relying on the treaty without specific legal and tax advice is not appropriate, and a cross-border estate plan should treat the treaty analysis as one component of a broader planning framework rather than as a complete solution.

Planning Strategies for US Citizens in the UK

Using the Unified Credit and Annual Exclusions

The most straightforward estate planning tool available to US citizens is the lifetime unified credit — the exemption that shelters up to $13.61 million of assets from federal estate tax at current rates. Furthermore, annual gifts of up to $18,000 per recipient (2024 figure) can be made free of both gift tax and the lifetime exemption, allowing gradual transfer of wealth without utilizing the exemption. Additionally, unlimited gifts to a US citizen spouse are exempt from US gift tax, which means wealth can be shifted between spouses to equalize estates and maximize the use of both spouses' exemptions on the survivor's death.

However, gifts to a non-US citizen spouse — even one living in the UK — do not qualify for the unlimited marital deduction under US law. Specifically, gifts to a non-citizen spouse are subject to an annual exclusion of $185,000 (2024 figure, indexed for inflation) rather than the unlimited deduction available for gifts to US citizen spouses. Consequently, US citizens married to a British or other non-US citizen spouse face additional planning constraints that require careful management, and the use of a qualified domestic trust (QDOT) at death may be necessary to defer estate tax on assets passing to the non-citizen survivor.

Trusts, Life Insurance and Business Interests

For US citizens with larger estates, trust planning can be an effective way to remove assets from the US taxable estate while providing for family members. Notably, an irrevocable life insurance trust (ILIT) can hold a life insurance policy outside the estate, allowing the death benefit to pass to beneficiaries free of estate tax if structured correctly. Furthermore, family limited partnerships and limited liability companies can be used to transfer business interests at a discount to their underlying value, effectively allowing more assets to pass within the available exemption.

However, UK tax considerations must be assessed alongside the US planning for each of these strategies. For example, a trust that is effective for US estate tax purposes may create UK IHT charges at ten-year anniversaries and on exit from the trust, as well as income tax complications for UK-resident beneficiaries. Therefore, any trust structure implemented for cross-border families must be reviewed by advisers who understand both the UK and US tax consequences of the arrangement simultaneously — a structure optimized for one side of the Atlantic can easily create unexpected liabilities on the other.

Case Study: US Citizen in London with UK Estate

Background

Our team worked with a US citizen who had lived in London since 2001 and had accumulated a UK estate consisting of a family home in Wimbledon worth approximately £1.8 million, an ISA and investment portfolio totaling £620,000, a defined contribution pension of £890,000, and a 30% shareholding in a UK trading company valued at approximately £1.4 million. Total UK assets were approximately £4.7 million, equivalent to roughly $6 million at the time of our review. The client was 58 years old, had a British-citizen spouse, and had never undertaken any US estate planning.

Analysis and Recommendations

Our analysis confirmed that the client's worldwide estate was subject to US estate tax, with the UK assets alone approaching 44% of the then-current $13.61 million exemption. Furthermore, we identified that the client had also acquired a deemed UK domicile after more than 15 years of UK residence, triggering potential UK IHT exposure on the worldwide estate. Consequently, we coordinated with a UK solicitor to implement a comprehensive plan that included maximizing annual gift exclusions to children over a rolling program, reviewing the pension nomination to ensure it was structured to minimize both UK IHT and any US estate tax exposure, and beginning a business interest transfer program using the company valuation discounts available under US law. Additionally, we modeled the impact of the 2025 sunset on the client's position and recommended that significant gifting be completed before year-end 2025 to lock in the current higher exemption level.

Get in Touch

At US-UK Tax, our cross-border specialists help US citizens living in the United Kingdom understand and manage their exposure to US estate tax on UK assets before it becomes a problem for their families. Furthermore, we coordinate with UK solicitors and financial advisers to ensure that estate plans work efficiently on both sides of the Atlantic, covering US estate and gift tax, UK IHT, trust planning, and pension strategy in a single integrated review.

To discuss your estate planning position and the US tax implications of your UK assets, contact our team in confidence today. Reach us by email at hello@us-uktax.com, by phone on 0333-8807974, or visit https://www.us-uktax.com/contact/ to book a consultation.

Conclusion

US estate tax on UK assets is a genuine and significant risk for every US citizen living in the United Kingdom, regardless of how long they have been resident there. Furthermore, the interaction between the US worldwide estate tax system and UK inheritance tax creates a potential for double taxation that requires specific cross-border planning to manage effectively. Moreover, the scheduled sunset of the elevated exemption after 2025 makes the current period an unusually important window to review and implement estate planning strategies. Consequently, US citizens in the UK should not defer this planning — the cost of inaction is measured in hundreds of thousands of dollars of avoidable tax paid by the next generation.

Contact US-UK Tax today to begin a confidential review of your UK estate and US tax exposure.

Contact Us

US-UK Tax | hello@us-uktax.com | 0333-8807974

https://www.us-uktax.com

FAQs

Q: Are US citizens in the UK subject to US estate tax on UK property?

Yes. US citizens are taxed on their worldwide estate regardless of residence. Furthermore, UK property, bank accounts, and investments are all included in the US gross estate at death.

Q: What is the US estate tax exemption for 2025?

The exemption is approximately $13.61 million per individual for 2024, with 2025 figures indexed for inflation. Additionally, this exemption is scheduled to be reduced significantly after 31 December 2025 unless Congress acts.

Q: Does the US-UK estate tax treaty eliminate double taxation?

The treaty helps allocate taxing rights and provides credits to reduce double taxation. However, it does not eliminate the charge in every case, and specialist advice is needed to assess the treaty application.

Q: Is my UK pension included in my US taxable estate?

Generally, no for undrawn defined contribution pensions held in trust. Furthermore, the position depends on specific scheme rules and benefit nominations, so each pension arrangement should be reviewed individually.

Q: Can I gift UK assets to my British-citizen spouse without US gift tax?

Gifts to a non-US citizen spouse are subject to an annual exclusion of $185,000 rather than the unlimited deduction. Additionally, a QDOT trust may be needed at death to defer estate tax on assets left to a non-citizen spouse.

Q: When should I start US estate planning as a US citizen in the UK?

As early as possible, and urgently before the end of 2025, given the scheduled exemption reduction. Furthermore, the longer planning is deferred, the fewer options are available and the greater the potential estate tax exposure becomes.