Cross-Border IHT for UK Migrants

For migrants to the UK, inheritance tax exposure is fundamentally a question of tax residence over time, not of citizenship, visa, or the location of assets at a given moment. The framework was reformed on 6 April 2025: the old domicile-based system was replaced with a residence-based regime that ties worldwide IHT exposure to a cumulative residence count. Understanding the residence count, the tail rules that apply after leaving the UK, and the interaction with visa status is the starting point of any cross-border estate plan for someone who has come to the UK from another country.

This article is for migrants, expats, and dual-resident families navigating UK IHT. It starts where the planning starts: with status and residence, not with assets.

The status test that determines your IHT exposure

Before considering assets, structures, or transfers, the first question is whether the individual is a long-term UK resident for IHT purposes. The 6 April 2025 reform created a single, residence-based test that replaced the domicile concept.

A person is a long-term UK resident in a tax year if they have been UK-resident under the Statutory Residence Test in at least 10 of the previous 20 tax years. The count is cumulative across the tax years; a year is either in or out of the count and there is no partial-year credit.

Visa category does not change the IHT timeline

The IHT residence count operates on UK tax residence as determined by the Statutory Residence Test, not on the visa under which the migrant arrived. A Skilled Worker visa holder, a Health and Care Worker visa holder, a Family visa holder, and a Global Talent visa holder are all measured by the same residence count. ILR (Indefinite Leave to Remain) and naturalisation as a British citizen do not on their own create IHT exposure.

What ILR and naturalisation do is remove the immigration constraint on remaining UK-resident over many years. A migrant who arrived on a short-term work visa and never extended would typically fall out of UK residence and not approach the 10-year long-term threshold. A migrant who progressed to ILR and then to naturalisation is structurally on track to cross the threshold and acquire long-term resident status for IHT.

The Statutory Residence Test for migrants

UK tax residence in each tax year (6 April to 5 April) is determined by the Statutory Residence Test. The test combines automatic UK and automatic overseas tests with sufficient-ties tests that count days spent in the UK alongside personal ties. A migrant who is physically present in the UK for 183 days or more in a tax year is automatically UK-resident for that year.

For incoming migrants, the year of arrival is often a split year under the SRT, where part of the year is treated as non-resident and part as resident. Split-year treatment can affect the IHT timeline because only fully-resident years count toward the 10-out-of-20 test.

What worldwide exposure looks like for a long-term resident

Once a migrant becomes a long-term UK resident, all assets worldwide fall within the scope of UK inheritance tax. This includes property in the country of origin, foreign bank accounts, foreign investment portfolios, foreign business interests, and overseas pensions in some structures.

For migrants from countries with substantial property values (for example, an inherited family home in India, a Buy-to-Let in Pakistan, an apartment in Mumbai, a flat in Dubai, or a house in South Africa), this can mean an IHT charge on assets the family does not consider to be 'UK assets' at all. The 40 percent rate on the value above the available nil-rate band applies regardless of where the asset sits.

The tail period after leaving the UK

Migrants who become long-term UK residents and then leave the UK do not immediately lose worldwide IHT exposure. A tail period applies: the individual remains exposed to UK IHT on worldwide assets for a defined number of years after departure, depending on how long they were UK-resident before leaving.

The tail period scales from 3 years (for those at the lower end of long-term residence) to 10 years (for those who were UK-resident for 20 of the prior 20 tax years before leaving). The implication is that an emigrating migrant cannot simply move country to escape UK IHT; the worldwide exposure persists for years.

Treaty relief for migrant estates

The UK has bilateral inheritance/estate tax treaties with a small number of countries: the United States, Ireland, France, India, Pakistan, Sweden, Switzerland, the Netherlands, and South Africa. These treaties allocate primary taxing rights between the two jurisdictions and provide mechanisms to avoid or reduce double taxation.

For migrants from non-treaty countries (which is most of the world), relief from double taxation in cross-border estate scenarios depends on unilateral credit relief under UK domestic rules and equivalent provisions in the other jurisdiction. The combination can sometimes deliver full relief, but the mechanism is more fragile than under a treaty and benefits from regulated tax advice.

Practical planning levers for migrants

Track the residence count

The single most important record for a migrant approaching long-term residence is a clear count of UK tax years to date. Year of arrival, any years of departure, and split-year treatment all affect the count. HMRC's residence pages and a simple spreadsheet kept across the migration journey are the basis of all later planning.

Time large lifetime transfers before crossing the threshold

Lifetime gifts made before the migrant becomes a long-term UK resident are not within the worldwide UK IHT scope, even if the donor later becomes long-term resident. For migrants with substantial overseas assets and a planned UK trajectory, executing lifetime transfers before the 10-year threshold can permanently reduce exposure.

Use the spouse exemption with care

Transfers between spouses are exempt from UK IHT only where both spouses have the same long-term resident status. Where one spouse is a long-term UK resident and the other is not, the spouse exemption is capped at a limited amount unless the non-long-term-resident spouse elects to be treated as long-term resident.

Plan for the tail before leaving

Migrants who have become long-term UK resident and plan to emigrate need to model the tail period and consider whether transfers, structures, or non-UK domicile changes can mitigate exposure during the tail. The strategy depends on the destination country, treaty position, and family structure.

Documentation specific to migrant estates

Cross-border estates need documentation that purely UK estates do not. Birth certificates, marriage certificates, foreign property title deeds, foreign tax residency certificates, and prior UK visa documentation are all relevant to the executor years later. Migrants should keep these documents accessible (with certified translations where needed) alongside the standard UK estate paperwork.

Where the migrant has children born outside the UK or holds prior visas (Skilled Worker, Health and Care Worker, Family, Global Talent, Tier 1 Investor or its predecessors), the documentation chain from entry through ILR and naturalisation is sometimes needed to evidence the residence history for HMRC.

Common pitfalls for migrant cross-border estates

The most common pitfall is the assumption that foreign assets are outside UK IHT scope because they are 'in another country'. The residence-based regime does not work that way: once long-term UK resident, worldwide assets are in scope. A second common pitfall is failure to update wills after migration: a will drafted in the country of origin may not be effective in the UK and may not deal correctly with UK-situated assets. A third pitfall is the spouse exemption cap where the spouses have mismatched long-term resident status.

Important: This article is for general information and does not constitute regulated financial advice or legal advice. UK inheritance tax rules for migrants changed substantially from 6 April 2025 and continue to be developed through HMRC guidance. Cross-border estate planning involves UK and foreign tax rules and benefits from advice from a UK tax adviser experienced in cross-border estates and, where relevant, advice in the other jurisdiction.

Frequently asked questions

Does my visa category affect my UK inheritance tax exposure?

Not directly. The UK IHT residence count is based on tax residence under the Statutory Residence Test, not on the immigration status the migrant holds. Skilled Worker, Health and Care Worker, Family, Global Talent, and other visa categories are all measured by the same residence count over a 20-year window.

Do I need to be a British citizen to be exposed to UK IHT on worldwide assets?

No. Naturalisation as a British citizen does not on its own create IHT exposure on worldwide assets. The trigger is becoming a long-term UK resident, which is determined by tax residence accumulated over the 10-out-of-20-year test, not by citizenship or settled status.

What happens to my IHT exposure if I leave the UK?

If you are a long-term UK resident when you leave, a tail period applies during which your worldwide assets remain within the UK IHT scope. The tail runs between 3 and 10 years depending on how long you were UK-resident before leaving. Planning before departure is essential to manage the tail effectively.

Can my country-of-origin will deal with my UK property?

Sometimes, but with risks. A foreign-drafted will may not meet UK formality requirements, may not deal correctly with UK-situated assets, and may not nominate a UK executor. Migrants with assets in two or more jurisdictions usually benefit from a separate UK will dealing with UK-situated assets alongside the will in the country of origin, drafted to avoid revocation conflicts.

Does a double taxation treaty help my migrant estate?

If your country of origin has a UK estate tax treaty (the list includes the US, Ireland, France, India, Pakistan, Sweden, Switzerland, the Netherlands, and South Africa), yes, the treaty allocates primary taxing rights and provides relief from double taxation. For non-treaty countries, relief depends on unilateral credit relief, which is less predictable and benefits from regulated tax advice.

Where can I check the current UK IHT rules for migrants?

The authoritative source is the HMRC Inheritance Tax Manual and the gov.uk inheritance tax pages, which were updated to reflect the 6 April 2025 residence-based regime. For visa and residence status, the gov.uk immigration pages and the Statutory Residence Test guidance are the operative references. Migrant-specialist advisers can interpret the interaction.