Harnett Accontants

Harnett & Co | Chartered Accountants, Kingston upon Thames
Global House Business Centre 1 Ashley Avenue Epsom Surrey KT18 5AD
ICAEW Authorised Practice
01372253100
International Tax | Harnett & Co Chartered Accountants Kingston upon Thames Skip to main content
Specialist Services

International
Tax

Living, working or investing across borders creates tax complexity that domestic advisers are not always equipped to handle. We advise individuals and businesses with cross-border tax situations - from arriving in the UK for the first time to managing overseas income, assets and corporate structures.

📞 01372253100
Cross-border taxation

Whether you have arrived in the UK or are leaving it, your tax obligations change significantly

The UK's international tax rules are among the most complex in the world. Whether you are a foreign national working in the UK, a UK national returning from abroad, an individual with overseas investments or a business trading across borders, the interaction between UK tax law, foreign tax systems and double tax treaties requires specialist knowledge to navigate correctly.

The West London and Surrey area is home to a large and diverse international community, including professionals on secondment, executives with overseas income, non-domiciled individuals with foreign assets and entrepreneurs running businesses that operate in multiple countries. These situations cannot be handled using a standard UK self assessment approach - they require an understanding of residence rules, domicile status, remittance basis taxation and treaty relief.

We have extensive experience advising clients with cross-border tax situations. We advise on UK tax residence under the Statutory Residence Test, the tax implications of the non-domicile rules following the significant reforms that came into effect from April 2025, overseas income reporting, double tax treaty claims and the disclosure of offshore assets and income not previously declared to HMRC.

Statutory Residence Test advice - clear determination of whether you are UK tax resident in any given tax year and the implications for what income and gains are taxable in the UK
Non-domicile and new arrivals regime - advice on the post-April 2025 rules for individuals who are not UK domiciled or have recently arrived in the UK
Overseas income correctly reported - foreign employment income, dividends, rental income, bank interest and pension income all reported on the foreign pages of your self assessment return
Double tax treaty relief claimed - where the UK has a treaty with the country in which the income arises, relief from double taxation is available and correctly claimed
Non-resident landlord scheme - UK rental income tax compliance for landlords who are not UK resident, including HMRC registration and self assessment returns
Worldwide Disclosure Facility - voluntary disclosure of offshore income and assets not previously declared to HMRC, achieving the lowest available penalty rates
What we cover

International tax services for individuals and businesses

From determining UK tax residence through to corporate cross-border structures, we cover the full range of situations where UK tax meets overseas jurisdictions.

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Statutory Residence Test
Detailed analysis of your UK tax residence position under the Statutory Residence Test for any given tax year. Includes automatic overseas tests, automatic UK tests and the sufficient ties test. Critical for anyone arriving in, leaving or spending significant time in the UK.
Foundational
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Non-Domicile and New Arrivals
Advice on the new four-year foreign income and gains regime introduced from April 2025, which replaced the remittance basis for newly UK-resident individuals. Planning for the transition from the old non-dom rules and advice on the new regime for recent arrivals.
Post-April 2025
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Overseas Income Reporting
Self assessment returns including the foreign pages, covering overseas employment income, dividends from foreign companies, foreign rental income, bank interest from overseas accounts, foreign pension income and overseas capital gains. All foreign tax credit relief calculated and claimed.
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Double Tax Treaty Relief
The UK has double tax treaties with over 130 countries. We identify which treaty applies to your income, determine the correct treatment under the treaty - exemption, reduced rate or credit relief - and make the appropriate claim on your return or through treaty clearance.
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Expatriate and Secondment Tax
UK tax advice for employees on international secondment, including split-year treatment when arriving or departing mid-year, overseas workday relief, PAYE on employment income and the interaction with overseas social security obligations.
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Non-Resident Landlord Scheme
Registration and compliance for UK landlords who are not UK resident. Approval to receive UK rental income gross rather than subject to basic rate withholding by the letting agent, plus annual self assessment returns covering UK rental income and any UK capital gains on disposal.
Landlords
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Worldwide Disclosure Facility
Voluntary disclosure to HMRC of overseas income, gains and assets not previously declared, using HMRC's Worldwide Disclosure Facility. Unprompted disclosure via this facility results in the lowest available penalty rates. We calculate the full liability, prepare the disclosure and negotiate with HMRC.
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Cross-Border Business Structures
Tax advice for UK businesses trading overseas and overseas businesses operating in the UK. Permanent establishment analysis, transfer pricing basics for smaller groups, controlled foreign company rules and the tax treatment of overseas subsidiaries and branches.
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Foreign Currency and Assets
UK tax treatment of gains and income arising in foreign currencies, overseas investment accounts, foreign pension schemes, offshore bonds and the tax consequences of remitting funds from overseas. Particularly relevant for individuals with assets in multiple countries.
UK tax residence

The Statutory Residence Test - determining whether you are UK tax resident in any given year

The Statutory Residence Test (SRT) has applied since April 2013 and provides a structured framework for determining whether an individual is UK tax resident in any given tax year. The test matters because a UK tax resident is generally liable to UK tax on their worldwide income and gains, while a non-UK resident is generally only liable on UK-source income.

The SRT works through a series of tests in order. Automatic overseas tests determine when you are definitely not UK resident regardless of ties. Automatic UK tests determine when you are definitely UK resident. If neither automatic test applies, the sufficient ties test looks at the number and nature of your connections to the UK and the number of days spent here to determine residence status.

Split-year treatment is available in certain circumstances where an individual arrives in or departs from the UK mid-year, meaning only part of the year is treated as UK resident. Getting the split-year calculation right is important because it affects which overseas income and gains need to be declared on the UK return and from what date.

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Automatic Overseas Tests
If you meet one of the automatic overseas tests you are not UK resident for that year regardless of any other factors. Key conditions include spending fewer than 16 days in the UK (if UK resident in any of the previous 3 years), or fewer than 46 days and no UK home, working full-time overseas with no significant UK work days.
Under 16 days: definitely not resident Working full-time overseas
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Automatic UK Tests
If you meet one of the automatic UK tests you are UK resident regardless of other factors. You are automatically UK resident if you spend 183 or more days in the UK in the tax year, have your only home in the UK for 91 or more consecutive days (of which at least 30 are in the tax year), or work full-time in the UK.
183+ days: automatically resident Only home in the UK
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Sufficient Ties Test
If neither automatic test determines residence, the sufficient ties test applies. This counts the number of UK ties you have - family, accommodation, work, 90-day tie and country tie - and combines this with the number of days spent in the UK to determine residence. The threshold varies depending on whether you were UK resident in prior years.
Complex - seek advice before travelling
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Split-Year Treatment
Where you arrive in or depart from the UK mid-year and meet certain conditions, the tax year is split into a UK resident part and a non-UK resident part. Only income and gains arising in the UK resident part of the year are fully within the scope of UK tax. Eight split-year cases apply and each has different conditions.
Arrival and departure cases 8 cases available
Non-domicile and new arrivals

The non-dom rules changed significantly from April 2025 - understanding the new regime is essential

Important: Non-dom rules reformed from 6 April 2025
The remittance basis of taxation for non-domiciled individuals was abolished from 6 April 2025 and replaced with a new four-year foreign income and gains (FIG) regime. Individuals who were already claiming the remittance basis also need to consider the transitional arrangements. The rules have changed materially and anyone who was claiming the remittance basis or who has recently arrived in the UK should seek updated advice.

Under the new regime, individuals who have not been UK tax resident in any of the previous ten tax years can elect to be taxed only on UK-source income and gains during their first four years of UK residence, with foreign income and gains exempt from UK tax during this period. This is the new four-year FIG regime and is broadly more straightforward than the old remittance basis but with stricter time limits.

After the four-year period expires, the individual becomes subject to UK tax on their worldwide income and gains in the same way as a UK-domiciled resident. The long-term residence basis charge that applied under the old rules no longer exists. Individuals who had been long-term UK resident non-doms and were not caught by the transitional provisions are now fully within the worldwide basis.

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New Four-Year FIG Regime
Available to individuals not UK resident in any of the previous 10 tax years. Foreign income and gains exempt from UK tax for the first 4 years of UK residence. No remittance basis charge. Simpler to operate than the old rules.
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Transitional Arrangements
Individuals who were claiming the remittance basis before April 2025 have access to certain transitional arrangements including a temporary repatriation facility for pre-April 2025 foreign income and gains. This is time-limited and requires careful planning.
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Overseas Workday Relief
Relief for employment income relating to duties performed outside the UK continues to be available in modified form under the new regime, subject to conditions. Important for executives and professionals who split their working time between the UK and overseas.
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Reporting Requirements
Even under the FIG regime, a UK self assessment return is required and the election must be made. After the four-year period, worldwide income and gains must be reported in full. We ensure the correct treatment is applied in each tax year and all deadlines are met.
Double tax treaties

The UK has treaties with over 130 countries - but the relief must be correctly claimed to be effective

Double taxation arises when the same income or gain is taxable in two countries - for example, rental income from a French property that is taxable in France and, because you are UK resident, also within the scope of UK tax. Double tax treaties determine which country has primary taxing rights and provide relief in the other country, usually through an exemption or a credit for foreign tax paid.

Simply paying foreign tax does not automatically give you UK tax relief. The treaty must be identified, its provisions applied to your specific income, and the relief correctly claimed on your UK self assessment return through the foreign tax credit relief pages. Incorrectly claiming or omitting treaty relief is one of the most common errors on returns for individuals with overseas income.

The treatment varies significantly between treaties and between different types of income. Dividends, interest, royalties, employment income and rental income are all treated differently, and some treaties contain provisions that are more favourable than the standard credit method. We review the relevant treaty for each client and ensure the maximum available relief is claimed.

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United States The UK-US treaty covers employment income, dividends, interest, royalties and pensions. Particularly relevant for US citizens or green card holders resident in the UK, where both countries may assert taxing rights. Pension treatment under the treaty requires careful analysis.
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France The UK-France treaty covers rental income from French property, French-source dividends and employment income for cross-border workers. French tax on rental income generally receives credit relief against the UK liability.
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Germany Relevant for UK residents with German employment income, German investment income or German property. The treaty allocates taxing rights and determines whether credit or exemption method applies depending on the income type.
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UAE and Gulf States The UK has a treaty with the UAE. Relevant for individuals returning from working in the Gulf, or those with ongoing income sources there. The interaction with the UK SRT is particularly important for those who spent time working in the region.
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India The UK-India treaty is frequently relevant for the significant Indian-origin community in West London and Surrey. Covers employment income, dividends, interest and pensions. Domicile status under Indian law may also interact with UK IHT.
How we work

From understanding your position to filing a correct and complete return

International tax returns are more complex than domestic ones and require careful coordination of information from multiple sources and jurisdictions.

1

Residence and status review

We determine your UK tax residence status for each relevant year, apply the SRT and identify whether split-year treatment or any special regime applies to your situation.

2

Income and gains review

All overseas income sources and gains are identified and their UK tax treatment determined, including any treaty relief available. Foreign tax paid is collated and credit claims prepared.

3

Return preparation

Self assessment return prepared including all relevant supplementary pages - foreign income, capital gains, residence and remittance basis pages where applicable - and submitted by the online deadline.

4

Ongoing planning

We advise on changes to your situation that may affect your tax position - planned relocations, new overseas income sources, changes in the rules - so you are never caught unprepared.

Who we help

International tax clients we work with regularly

Our international tax clients come from a wide range of backgrounds. What they share is a cross-border dimension to their tax affairs that requires specialist handling.

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Expatriates and Returning UK Nationals
Individuals arriving in the UK for work or returning after time abroad. Advice on residence status, split-year treatment, overseas workday relief and the tax treatment of income and assets built up while overseas.
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Foreign Nationals Living in the UK
Individuals from overseas who are UK resident but may have overseas income, foreign bank accounts, overseas property or pension entitlements in their home country. Advice on the new four-year FIG regime and reporting of all overseas sources.
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Non-Resident Landlords
UK property owners who are not UK resident - including British nationals living abroad and overseas nationals who own UK investment property. Registration under the Non-Resident Landlord Scheme and annual UK tax returns for rental income and capital gains.
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Executives with International Compensation
Senior employees and directors with compensation packages that include overseas share awards, bonuses paid by foreign entities, employer-funded accommodation overseas or pension contributions to foreign schemes. Each element requires specific analysis.
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Investors with Overseas Assets
UK residents with foreign investment accounts, overseas shares and funds, offshore bonds, foreign pension funds or savings accounts held outside the UK. All investment income and gains reported correctly with appropriate treaty relief and foreign tax credits claimed.
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Businesses Trading Across Borders
UK companies with overseas operations or subsidiaries, and overseas businesses with a UK presence. Permanent establishment analysis, the tax treatment of intra-group transactions and compliance with UK corporation tax on overseas income.
Common questions

International tax questions answered

Your liability to UK tax depends on your residence status under the Statutory Residence Test. Once you become UK tax resident you are generally liable to UK income tax and capital gains tax on your worldwide income and gains. However, if you have not been UK resident in any of the previous ten tax years, you may be able to elect for the new four-year foreign income and gains regime, which exempts overseas income and gains from UK tax during your first four years of UK residence. The date from which you are treated as UK resident within the year depends on whether split-year treatment applies - this is determined by which of the eight split-year cases your circumstances fall into. Getting the residence determination right in your first year is important as it affects what needs to be declared.
Once you cease to be UK tax resident you are generally not liable to UK income tax on overseas income. However, UK-source income - such as rental income from UK property, UK employment income or dividends from UK companies - remains within the scope of UK tax even for non-residents, though double tax treaties may affect how much UK tax is actually due. UK capital gains tax on UK residential property also applies to non-residents since April 2015, and has applied to all UK property since April 2019. You may need to file a UK self assessment return for the year of departure and potentially for subsequent years if you have UK income sources. Correctly documenting your departure and the date from which you become non-resident is also important in case HMRC later questions your residence status.
If you are UK tax resident, your overseas income is generally also within the scope of UK tax. However, where the UK has a double tax treaty with the other country, you are usually protected from being fully taxed twice. The treaty will determine whether the other country or the UK has primary taxing rights on the income, and will provide relief in the other country - typically through an exemption or a credit for the foreign tax paid. Where there is no treaty, unilateral relief is available in the UK for foreign tax paid on income that is also taxable in the UK. The relief is given as a credit against UK tax on the same income, capped at the lower of the foreign tax and the UK tax on that income. This means you pay at the higher of the two tax rates, not the combined total.
The remittance basis of taxation, which allowed non-domiciled UK residents to elect to pay UK tax only on UK income and on overseas income remitted to the UK, was abolished from 6 April 2025. It was replaced with a new four-year foreign income and gains (FIG) regime available to individuals who have not been UK tax resident in any of the ten years before their current UK residence. Under the FIG regime, overseas income and gains are exempt from UK tax for the first four years of UK residence. After four years the individual is taxable on worldwide income and gains in the same way as a UK-domiciled resident. Individuals who were already claiming the remittance basis before April 2025 have access to transitional arrangements including a temporary repatriation facility. The long-term UK resident charge (the former remittance basis charge of £30,000 or £60,000) no longer applies under the new rules.
You should seek advice and consider making a voluntary disclosure through HMRC's Worldwide Disclosure Facility as soon as possible. HMRC receives information about overseas bank accounts held by UK residents through the Common Reporting Standard, under which over 100 jurisdictions now automatically exchange account information with HMRC annually. This means HMRC is likely to have information about your overseas accounts already, or will receive it. An unprompted voluntary disclosure results in significantly lower penalties than a prompted one. For a careless error, an unprompted disclosure can result in a 0% penalty on the underpaid tax. For offshore matters the penalty regime is more severe than for domestic errors, with offshore penalties of up to 200% for deliberate and concealed behaviour in non-cooperative jurisdictions. Acting before HMRC contacts you is nearly always the best outcome available.
There is no single answer as the Statutory Residence Test is multifactorial. The automatic overseas tests mean you are definitely not UK resident if you spend fewer than 16 days in the UK in the tax year (if you were UK resident in any of the previous three years) or fewer than 46 days (if you were not UK resident in any of the previous three years). Above these thresholds the sufficient ties test applies, and the number of days you can spend without becoming resident depends on the number of UK ties you have - family, accommodation, substantive work in the UK, a 90-day tie or the country tie. Someone with no UK ties could spend up to 182 days without becoming resident. Someone with four or more ties could become resident with as few as 46 days spent in the UK. Day counting under the SRT requires care and should be reviewed each year.
UK rental income remains within the scope of UK income tax regardless of whether you are UK resident. You should register with HMRC's Non-Resident Landlord Scheme, which allows you to receive your rental income gross (without the letting agent or tenant withholding basic rate tax) once HMRC approves your application. You will also need to file an annual UK self assessment return reporting the rental income, deducting allowable expenses and paying UK tax on the net profit. Your country of residence may also tax the UK rental income under its own rules, and the double tax treaty between the UK and your country of residence will determine whether you receive relief from double taxation. When you eventually sell the property, UK capital gains tax will apply on the gain and a 60-day report must be filed with HMRC within 60 days of completion.
Related services
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Self Assessment and Personal Tax
International tax issues are handled within your UK self assessment return. We prepare the complete return including all foreign pages, residence pages and capital gains pages, ensuring every overseas source is correctly reported and all available reliefs are claimed.
Learn more ›
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Property and Landlord Tax
Non-resident landlords with UK property have specific compliance obligations. We handle Non-Resident Landlord Scheme registration, annual returns for UK rental income and the 60-day CGT report and payment when UK property is sold.
Learn more ›
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Tax Investigation Support
If HMRC opens an enquiry into your overseas income or assets we represent you throughout the investigation. We also handle voluntary disclosures through the Worldwide Disclosure Facility for clients with undisclosed offshore income or assets.
Learn more ›
International tax advice

Cross-border tax situations need specialist advice

Whether you have recently arrived in the UK, have overseas income to declare or are considering a move abroad, talk to us. We advise individuals and businesses with international tax situations across West London and Surrey.

📞 01372253100