UK Inheritance Tax for Non-Residents and the Non-Dom Reform 2026

Most international investors who own UK property think about rental and capital gains tax; but the most critical and most often missed matter is inheritance tax (IHT). The major "non-dom" reform that came into force on 6 April 2025 shifted the system from domicile-based to residence-based. This guide explains what the reform introduced, why it directly concerns foreign property owners, and the right professional support.

How Does IHT Work, and What Changed in 2025?

Inheritance tax (IHT) is a tax charged on the value of a person's estate above a certain threshold on their death. The standard rate is 40% on the value above the "nil-rate band" (the tax-free threshold, currently £325,000); an additional "residence nil-rate band" of up to £175,000 may also apply when passing a home directly to direct descendants (children/grandchildren), tapering away for very large estates. Transfers between spouses are generally exempt.

Historically, whether a person's worldwide assets were subject to IHT depended on the concept of "domicile". The reform that took effect on 6 April 2025 changed this fundamentally: the concept of domicile (and "deemed domicile") was abolished for IHT and replaced with a residence-based system. What now matters is not where you are considered "domiciled" but how many tax years you have been UK resident.

The Most Critical Point: UK Property Is Always in Scope

The most important fact a foreign property investor must know is this: both before and after the reform, UK-situated (UK-situs) assets are always within the scope of UK IHT. This includes UK residential property. So even a foreigner who has never lived in the UK and will never become a "Long-Term Resident" has their London flat subject to UK inheritance tax on their death.

This becomes clear with a concrete example: if an investor living in Dubai who has never been UK resident owns a London flat worth £1,000,000, that flat is their UK-situs asset. On their death, potentially 40% IHT can arise on the value above the current nil-rate band (in a simplified example, on the £675,000 remaining after the £325,000 exemption). This is exactly why buying a UK property also creates a need for IHT planning; it should be planned with tools like life insurance, ownership structure and wills, alongside a qualified adviser.

"Long-Term Resident" (LTR) and Worldwide Assets

The new test the reform introduced is the concept of "Long-Term Resident" (LTR). A person is an LTR if they have been UK tax resident for at least 10 of the 20 tax years before the year in which a tax event (e.g. death) occurs. Once a person reaches LTR status, not only their UK assets but all their worldwide assets come into the scope of UK IHT.

This is a significant tightening compared with the previous system: the old "deemed domicile" rule was 15/20 (15 of the last 20 years); the new rule is 10/20. So people now come into worldwide IHT scope in 10 years instead of 15. The practical result: someone newly arriving in the UK is subject to IHT only on their UK assets for the first 10 years; from the 11th year, their worldwide assets also come into scope. For someone who has long lived abroad (for example in the Gulf) and never stayed in the UK for long, this reform is actually a clarity and often an advantage: their non-UK assets stay clear of UK IHT (only the UK property is in scope).

Leaving the Country: The "Tail" Rule

The reform prevents LTR status from being removed instantly by leaving the country. When an LTR leaves the UK, their worldwide assets remain in the scope of UK IHT for a further period (the "tail" period). This period depends on how long you were resident: 3 years for someone resident 10-13 years; increasing by one year for each additional year of residence; reaching a maximum of 10 years for those resident 20 years or more.

An important point: after 10 consecutive years of being non-UK resident, the 10/20 test "resets"; if the person returns to the UK, only the year of return and later count. (A modified test applies to those under 20.) These rules create a critical matter of timing, especially for high-net-worth individuals planning to move to or leave the UK, and absolutely require specialist planning. Furthermore, offshore trusts, "excluded property" rules and double-taxation treaties complicate this picture further; these are outside the scope of this article and require a specialist.

Optivest Note: Optivest is not a tax adviser or an estate-planning firm; IHT planning is the domain of a qualified tax adviser, a STEP-member specialist or an SRA-registered solicitor. But there is a fact Optivest can honestly highlight: buying a UK property means acquiring an asset that is always within IHT scope, even if the owner never lives in the UK. This is a factor to consider from the outset in the buying decision. Optivest's legal support (conveyancing) service handles the legal side of buying and selling, and can work in coordination with your tax/estate adviser in that process; but it does not do the IHT planning itself.

Important notice — not tax/legal advice: This article is for general information only and does not constitute tax, legal or estate-planning advice. IHT rules are extremely complex, vary greatly by personal circumstances (residence history, nationality, ownership structure, trusts), and thresholds/rates can be updated over time. Before making any decision, consult a qualified UK tax adviser, STEP specialist or SRA-registered solicitor, and confirm on gov.uk. Optivest does not provide tax or estate-planning services.

Frequently Asked Questions

If I have never lived in the UK, is my London flat subject to IHT?

Yes. UK-situated (UK-situs) assets — including UK residential property — are always within the scope of UK IHT, regardless of the owner's residence. Even the London flat of a foreigner who has never lived in the UK can be exposed to 40% IHT on the value above the nil-rate band (£325,000). Consult a qualified adviser for planning.

What does "Long-Term Resident" mean?

It is a person who has been UK tax resident for at least 10 of the 20 tax years before a tax event (e.g. death). Once an LTR, not only their UK assets but all their worldwide assets come into UK IHT scope. The old rule was 15/20; the new rule is 10/20, so scope is reached sooner (in 10 years).

What exactly did the 2025 reform change?

From 6 April 2025, IHT moved from a domicile-based system to a residence-based system; "domicile" and "deemed domicile" were abolished for IHT. The scope of worldwide assets now depends not on domicile but on whether you are a "Long-Term Resident" (the 10/20 rule). UK assets, as before, are always in scope.

If I leave the UK, does IHT end immediately?

No. If you are an LTR, after leaving the country your worldwide assets remain in scope for a "tail" period: 3 years for 10-13 years of residence, up to a maximum of 10 years with more residence. After 10 consecutive years non-resident, the test resets. This timing requires specialist planning.

What can I do to reduce IHT?

IHT planning is complex and depends on personal circumstances; tools like life insurance, ownership structure, wills and spousal exemption may be relevant, but each has its own rules and risks. These decisions must be made with a qualified tax adviser, STEP specialist or solicitor. This article gives general information, not personal advice.

In Summary, and How to Reach Us

The most critical inheritance-tax fact for foreign property owners is clear: a UK property is always within UK IHT scope, even if the owner never lives in the UK, and its value above the nil-rate band is exposed to the 40% rate. The 2025 reform replaced domicile with the "Long-Term Resident" (10/20) test for worldwide assets. So buying a UK property also requires IHT planning.

This planning should be done by a qualified tax/estate adviser; Optivest does not provide this service, but runs the legal side of buying (conveyancing) in coordination with your adviser. Contact us or reach us on WhatsApp. See our legal support service for the legal process of buying, our investment consultancy service for investment planning, and our project listings for options.