Concept
UK tax is not citizenship-based. A British passport does not create a U.S.-style worldwide net. UK exposure starts with residence, then source, situs, company and trust connections, and — for inheritance tax — long-term residence. For an internationally mobile founder, investor or family it is a legal system to be modelled, not a relocation lifestyle checklist.
The post-6 April 2025 frame is decisive. HMRC states in the Residence and FIG Regime Manual that from 6 April 2025 all UK residents are taxed on the arising basis on worldwide income and gains, subject to the new Foreign Income and Gains (FIG) regime for qualifying new residents. The old non-dom remittance basis survives only for pre-6 April 2025 pools, transitional designations and legacy trust analysis.
This is general legal information, not individual tax advice. UK residence, treaty position, trust attribution, company residence and IHT exposure turn on facts and documents.
Residence
Everything starts with the Statutory Residence Test: automatic overseas tests, then automatic UK tests, then sufficient ties. 183 or more UK days make a person UK resident without further analysis. Split-year treatment is not a separate status — it applies only where a statutory case is met. Detail in UK tax residence.
Worldwide income and the FIG regime
A UK resident is normally taxed on worldwide income and gains as they arise. A qualifying new resident — broadly, UK resident after at least 10 consecutive non-resident tax years — may claim the 4-year foreign income and gains regime for eligible foreign income and gains in the first four UK tax years. Foreign employment income runs through Overseas Workday Relief for the same four-year window — capped at the lower of £300,000 or 30% of qualifying employment income — not on the assumption that all foreign salary is FIG. See worldwide income and gains, the FIG regime and overseas workday relief.
Transitional rules for former non-doms
Former remittance-basis users must separate post-6 April 2025 income and gains from historical pools. HMRC's HS264 helpsheet and TRF manual treat the Temporary Repatriation Facility as a separate designation regime: a flat 12% for designations in the 2025/26 and 2026/27 tax years, then 15% in 2027/28. Detail in the remittance basis after 2025 and non-dom changes from 2025.
Companies, trusts and funds
UK residence reaches through structures. A non-UK company managed and controlled from the UK can be UK resident or caught by the transfer-of-assets-abroad rules; a non-resident trust can attribute income and gains to a UK-resident settlor or beneficiary; a non-reporting offshore fund can convert a gain into income taxed at higher rates. See foreign companies, trusts and inheritance tax and offshore funds.
Treaties and foreign tax credit
Dual residence is common. A treaty can allocate residence and limit UK taxing rights, but HMRC's dual residence manual (INTM154020) confirms that treaty non-residence does not delete domestic UK residence or its filing duties. Relief for foreign tax runs through credit or treaty. See foreign tax credit and treaties.
Inheritance tax
From 6 April 2025 inheritance tax is residence-based, not domicile-based. HMRC's long-term UK resident guidance explains that a person UK resident for at least 10 of the previous 20 tax years is a long-term resident, within IHT on worldwide assets, with a three-to-ten-year tail after leaving. UK-situs assets are always in scope. Detail in trusts and inheritance tax.
Compliance and data
The UK rewards a defensible file. CRS and FATCA data reach HMRC and must match Self Assessment; a family office needs an ownership map, source-of-funds records and a document trail; an HMRC enquiry tests the evidence, not the label. See CRS, FATCA and HMRC data, family office records and HMRC enquiries and cleanup.
Arriving and leaving
Planning is pre-arrival, annual and departure-based. Pre-arrival work covers SRT modelling, FIG and OWR eligibility, portfolio design, trust review, company governance and IHT projection. Departure work covers split-year treatment, temporary non-residence and the UK property and IHT tail. See planning before UK residence and leaving the UK.
Q&A
Is UK tax based on citizenship
No. UK citizenship is not the equivalent of U.S. citizenship-based taxation. UK exposure turns on residence, UK source, UK situs, UK property, company and trust connections, and long-term residence for inheritance tax.
Did the non-dom regime survive after 6 April 2025
Not as the default for new foreign income and gains. The remittance basis was replaced by the FIG regime for qualifying new residents, with transitional rules for pre-6 April 2025 pools and the Temporary Repatriation Facility.
Is FIG the same as the remittance basis
No. FIG is a time-limited, residence-based relief for eligible foreign income and gains in the first four UK tax years. It is not a rule that taxes foreign income only when it is remitted to the UK.
Can a person be UK resident and treaty resident elsewhere
Yes. Dual domestic residence is common. A treaty may allocate residence for treaty purposes and limit UK taxing rights, while UK domestic filing duties remain.
When does worldwide inheritance tax exposure start
After long-term residence: UK resident for 10 of the previous 20 tax years. UK-situs assets are always within IHT; long-term residence extends it to worldwide assets, with a tail of three to ten years after departure.
Related
- UK tax residence
- Worldwide income and gains
- The FIG regime
- Overseas workday relief
- The remittance basis after 2025
- Non-dom changes from 2025
- Foreign companies
- Trusts and inheritance tax
- Offshore funds
- Foreign tax credit and treaties
- CRS, FATCA and HMRC data
- Family office records
- HMRC enquiries and cleanup
- Planning before UK residence
- Leaving the UK
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