Foreign Income and UK Tax

Introduction

Foreign income is one of the most commonly misunderstood areas of UK expatriate taxation.

The term “foreign income” sounds straightforward, and as a result many people assume:

• “My income arises outside the UK, so it must be foreign.”
• “I live abroad, therefore I am not UK tax resident.”
• “My investments are offshore, so UK tax does not apply.”
• “I can address the tax position when I eventually return.”

In reality, whether income remains outside the UK tax net depends heavily on UK residence status, which can change - sometimes unexpectedly - within a tax year.

UK residence rules are determined by the Statutory Residence Test (SRT). Where UK residence is established, the UK generally taxes individuals on a worldwide basis, subject to reliefs, exemptions and treaty provisions.

This means that, depending on the facts, the UK can potentially tax:

• foreign dividends
• foreign interest
• overseas rental income
• gains on foreign property
• foreign business income
• certain trust distributions
• foreign pension income
• in some cases, overseas employment income

Recent and forthcoming legislative changes increase the importance of understanding how these rules interact.

This article sets out the framework.

What “Foreign Income” Actually Means

Broadly, foreign income refers to income not sourced from the UK.

Common examples include:

Foreign dividends

From holdings such as:

• US equities
• EU-listed shares
• global ETFs
• overseas companies
• offshore funds
• international REITs

Foreign interest

From:

• overseas savings accounts
• offshore banks
• multi-currency accounts
• foreign currency deposits
• investment-linked accounts

Foreign rental income

From property located outside the UK, including (but not limited to):

• UAE
• Qatar
• Saudi Arabia
• Spain
• Portugal
• Cyprus
• Thailand
• Australia
• United States

Foreign business income

Including:

• consulting
• contracting
• freelancing
• director fees
• self-employment income
• entrepreneurial activity

Foreign capital gains

From the disposal of:

• overseas shares
• foreign property
• non-UK investment funds
• business interests
• digital assets

Foreign pension income

Tax treatment depends on:

• residence status
• domestic UK rules
• applicable double tax treaties
• UK classification of the pension

Whether any of the above falls within UK taxation depends primarily on residence, timing and structure.

Residency as the Key Determinant

UK taxation of foreign income is fundamentally driven by residence status.

If you are non-UK resident (with a clear SRT position)

The UK generally taxes only:

• UK-source income
• UK rental income
• UK property gains
• certain UK government pensions

Foreign income is typically outside UK scope.

If you are UK resident

The UK generally taxes worldwide income, including:

• foreign dividends
• foreign interest
• overseas rental income
• foreign gains
• certain overseas pensions

This can apply even where:

• income arises overseas
• funds remain outside the UK
• the host country applies low or no tax
• the individual considers themselves to have “left the UK some time ago”

Residence status is therefore critical.

How UK Residency Can Be Triggered Unexpectedly

UK residence can be triggered unintentionally through a combination of factors, including:

• extended visits to the UK
• maintaining accommodation that is available for use
• undertaking UK workdays (including remote work)
• family connections in the UK
• spending more days in the UK than in any other single country
• historic UK presence

The SRT operates through a system of days and ties. In some cases, relatively few UK days can result in residence if sufficient ties are present.

Once UK residence is established for a tax year, foreign income may fall within UK taxation for that year, subject to the availability and correct application of split-year treatment and other statutory provisions.

Legislative Changes Affecting Foreign Income

Recent Budgets and announced reforms have increased focus on foreign income exposure:

• Changes to rates, thresholds and allowances applicable to investment income, which may increase the effective tax burden for some taxpayers depending on circumstances.
• Abolition of the remittance basis for UK-resident non-domiciled individuals from 6 April 2025, replaced by a new 4-year Foreign Income and Gains (FIG) regime for individuals who become UK resident after 10 tax years of non-UK residence, alongside transitional provisions for pre-6 April 2025 income and gains.
• Residence-based IHT for long-term UK residents (from 6 April 2025): if you meet the “long-term UK resident” conditions, your overseas assets may be within scope of UK IHT on death or certain lifetime transfers (subject to detailed rules, transitional provisions and any applicable treaties).
• Changes to National Insurance treatment for overseas years
• Increased scrutiny of split-year treatment

These changes increase the importance of planning around residence and timing.

Commonly Misunderstood Categories of Foreign Income

1. Foreign Dividends

If an individual is UK resident in the year dividends are received:

• foreign dividends are generally taxable in the UK
• UK dividend tax rates apply
• foreign tax credits may be available, subject to limits

2. Foreign Interest

If UK resident:

• interest from offshore and foreign currency accounts is generally taxable
• interest is taxed at marginal income tax rates

3. Overseas Rental Income

Overseas rental income may:

• be taxed in the country where the property is located
• also fall within UK tax if UK residence applies
• rely on treaty relief to mitigate double taxation

4. Foreign Capital Gains

Potential issues include:

• differing tax years
• mismatched classifications
• limited treaty protection
• interaction with UK reporting rules

What Double Tax Treaties Do (and Don’t Do)

Double tax treaties:

• allocate taxing rights between countries
• provide mechanisms to relieve double taxation

They do not:

• prevent UK taxation where residence applies
• override UK residence rules
• remove reporting obligations
• eliminate mixed fund issues

Case Studies

The following case studies are simplified illustrations of common fact patterns. They are not comprehensive, do not represent typical outcomes, and the UK tax result can differ depending on residence status, split-year conditions, deductions, treaty relief, reporting requirements and how income/gains are classified for UK purposes.

Case Study 1 - The Dubai Investor With Overseas Dividends

Returned to the UK in February.
Split-year treatment was not available (or conditions were not met) in this scenario.
Foreign dividends fell within UK taxation for the year under the individual’s residence position (with any double tax relief dependent on the facts).
Key takeaway: if you hold dividend-paying portfolios, review the tax year of return, whether split-year applies, and the timing of distributions.

Case Study 2 - The Spain Expat With Rental Property Abroad

Spanish rental income taxed in Spain.
Returned to the UK in September; UK residence applied for the year.
UK tax applied to the rental income to the extent required under UK rules for that year, with double tax relief potentially available but not always eliminating double taxation in full.
Key takeaway: overseas property owners should track income periods, deductible expenses, and treaty/double tax relief mechanics, particularly in a return year.

Case Study 3 - The Qatar Expat with Offshore Interest

Assumed USD savings interest was “tax-free abroad”.
UK residence was triggered due to time spent in the UK under the SRT.
Interest was within scope of UK taxation for that tax year.
Where no foreign tax is paid, there may be no foreign tax credit, so UK tax can arise based on UK rates/allowances for the year.
Key takeaway: bank interest is easy to overlook - consider the residence position before relying on “offshore = outside UK tax”.

Case Study 4 - The Thailand Expat Who Sold Overseas Property

Sold overseas property in May and returned to the UK in July. Split-year treatment was not available (or conditions were not met) in this scenario. The gain fell to be considered under UK rules for that year; foreign tax relief can be complex where the overseas system and UK system classify the gain differently.

Key takeaway: before a disposal around a move, check residence timing, split-year eligibility, and how the asset/gain is classified under UK rules.

Case Study 5 - The Australia Returner

Disposed of Australian shares and returned mid-year. Australia taxed the gain; UK taxation was also relevant for the year under UK residence rules. Some treaties provide limited relief for certain capital gains, so overlapping tax outcomes can arise depending on the asset, the treaty terms and domestic rules.
Key takeaway: where gains are material, confirm treaty coverage for the specific gain and the UK residence position for that tax year.

Portfolio Income: Commonly Overlooked Issue in Offshore Investing

British expats often hold offshore portfolios in:

• USD
• EUR
• global funds
• offshore platforms
• overseas brokers
• international ETFs
• discretionary portfolios

Because these portfolios sit outside the UK, many assume they remain outside UK tax altogether.

However, for UK tax purposes, the location of the account or platform is not decisive. If UK residence applies in a tax year, portfolio income and gains may fall within UK scope depending on classification, timing and structure.

There are three common portfolio-related issues that arise.

Issue 1 - Portfolio Income Is Still Income

Offshore portfolios can generate:

• foreign dividends
• foreign interest
• fund distributions
• bond coupons
• REIT income
• realised gains from rebalancing or disposals

If an individual is UK resident in the relevant tax year, the UK generally taxes worldwide income and gains, subject to applicable reliefs.

This can apply regardless of:

• whether the account is held overseas
• whether the proceeds are retained offshore
• whether the host country taxes the income
• the currency in which assets are held

From a UK perspective, residence status and income classification are key.

Issue 2 - Investment Income and Changing UK Tax Rates

Recent and proposed UK tax changes have increased attention on income derived from investments.

Foreign dividends, interest and similar portfolio income may be taxed at UK rates applicable for the year in question, which can differ from rates applied to earned income and may change over time.

For expats who rely primarily on investment income - particularly in retirement - understanding how these rates apply once UK residence is triggered is important.

Issue 3 - Non-Reporting Funds

Many non-UK funds do not have UK reporting fund status.

This commonly affects:

• overseas ETFs
• foreign index funds
• local investment funds
• offshore discretionary portfolios

Where a fund is non-reporting, the UK may tax gains on disposal as income rather than capital gains if UK residence applies in that year. This treatment arises under the UK offshore funds rules: where an offshore fund does not have reporting fund status, gains on disposal can be treated as offshore income gains for UK tax purposes rather than capital gains. This difference in classification can materially affect the UK tax outcome and is not always identified where portfolios are built outside the UK system.

Mixed Funds

A mixed fund is a UK tax concept that is most relevant where the tax treatment depends on remittances to the UK (for example, under the historic remittance basis and, for some individuals, in relation to pre-6 April 2025 income and gains under transitional rules).
A mixed fund can arise when an offshore account contains a mixture of:

• Income
• Gains
• Interest
• Dividends
• rental receipts
• salary or business income
• capital transfers

Where the mixed fund rules are in point, UK legislation applies statutory ordering rules to determine the tax character of a remittance, and the outcome may not align with an individual’s expectations - particularly where accounts have been pooled over many years and records are incomplete.
The relevance of mixed funds (and whether remittance concepts apply at all) depends on an individual’s circumstances and the regime applicable for the tax year.

From 6 April 2025, most UK residents are taxed on the arising basis on worldwide income and gains; remittance concepts remain most relevant for pre-6 April 2025 income/gains and transitional cases.

The Year of UK Return

The tax year in which an expat returns to the UK often requires extra care, because foreign income and gains may become relevant to UK tax depending on residence status and split-year treatment.

This is due to:

• partial-year residence
• split-year conditions not being met
• timing of income receipts and asset disposals

Where UK residence applies for the year, worldwide income and gains may be brought into UK scope, even if generated earlier in the year or overseas.

Careful attention to timing is therefore critical.

How Foreign Income Links to Worldwide IHT Under the Long-Term UK Resident Rules

Under the UK’s long-term UK resident IHT framework (in force from 6 April 2025):
If an individual meets HMRC’s “long-term UK resident” conditions, their overseas assets may be within scope of UK IHT on death or certain lifetime transfers, subject to the detailed rules and any relevant treaty provisions.

This is sometimes summarised as a ‘10 out of 20 tax years’ test, but readers should rely on the statutory/HMRC definition for the relevant year.

This can include:

• foreign investments
• overseas property
• offshore bank accounts
• foreign pension interests

Foreign income interacts with this framework by contributing to asset accumulation and mixed fund complexity over time.

How UK Tax Exposure on Foreign Income Is Commonly Managed

There are several recognised ways in which UK tax exposure on foreign income may be managed or mitigated within the rules —
but outcomes depend entirely on individual facts, timing and legislation in force.

This section is an educational overview, not a recommendation.

1. Maintaining clear UK non-resident status

UK taxation of foreign income is primarily driven by residence.

This typically involves monitoring:

• days spent in the UK
• UK ties under the SRT
• availability of UK accommodation
• UK workdays
• family connections
• historic UK presence

Where an individual remains non-UK resident under the SRT, foreign income is generally outside UK scope.

2. Applying double tax treaties correctly

Double tax treaties can:

• allocate taxing rights
• reduce double taxation
• provide relief mechanisms
• clarify treatment of certain pensions and income types

However, treaty benefits generally depend on clear residence status and correct classification of income under UK law.

3. Considering the timing of a UK return

The timing of a return to the UK can materially affect the tax position.

Common considerations include:

• returning at the start of a tax year
• understanding split-year conditions
• reviewing income and disposals before return
• understanding when UK residence is triggered

Timing does not change the rules, but it can affect how they apply.

4. Addressing mixed funds before UK residence applies

Where offshore accounts contain mixed income, gains and capital, UK rules can produce unexpected outcomes.

In practice, this may involve:

• identifying clean capital
• separating income and gains
• improving record-keeping
• understanding remittance implications

The appropriate approach depends on the account history and documentation.

5. Understanding investment classifications

Investment structures built outside the UK may not align with UK tax rules.

This commonly includes:

• non-reporting funds
• offshore wrappers
• overseas discretionary portfolios
• local investment products

Understanding how these are classified under UK law is important if UK residence later applies.

6. Linking residency, investment and retirement planning

Foreign income planning in isolation can lead to gaps.

UK tax outcomes often depend on:

• residency position
• investment structure
• income timing
• long-term intentions
• potential UK return

Considering these together can help avoid unintended consequences.

A Structured Framework for Reviewing Foreign Income Exposure

A structured review of foreign income exposure typically includes:

Step 1: Confirm residence position
Days and ties under the SRT.

Step 2: Identify all foreign income sources
Dividends, interest, rent, gains, pensions and business income.

Step 3: Review treaty position by income type
Salary, dividends, property, pensions and self-employment.

Step 4: Identify mixed fund risks
Understand how offshore accounts are constituted.

Step 5: Review investment classification
Reporting vs non-reporting funds and wrappers.

Step 6: Assess return-year exposure
Split-year treatment and timing issues.

Step 7: Consider longer-term IHT exposure
Including the long-term UK resident rules.

Step 8: Revisit the position periodically
Changes in residence, family or assets can alter outcomes.

This framework is intended to highlight common risk areas, not prescribe actions.

Conclusion

Foreign income is one of the most complex areas of UK expatriate taxation - not because individuals are careless, but because the rules are detailed, fact-specific and often misunderstood. A common assumption persists:

“My income is foreign, so the UK cannot tax it.”

In practice:

• UK residence is the key trigger
• treaties reduce double tax, not UK tax itself
• mixed funds can create unexpected exposure
• investment classification matters
• timing of a return can be critical
• residence now drives IHT exposure as well

Foreign income itself is not the issue.
Lack of understanding of how the rules interact is.

This article is intended to improve that understanding.

This article is provided for general informational purposes only. It does not constitute tax advice, legal advice, financial advice, or a recommendation to take (or refrain from taking) any action. Tax outcomes depend on individual circumstances, the precise facts, and the law, treaty interpretation and HMRC practice in force at the relevant time (including changes announced but not yet enacted). No reliance should be placed on this article as a substitute for obtaining personalised advice from a suitably qualified professional.