American Expats and UK Tax Obligations
For American expats living in the UK, tax can quickly become more complicated than expected. Moving to Britain does not always mean leaving the US tax system behind. At the same time, living, working or investing in the UK may create obligations with HMRC.
This means many American expats need to think about two tax systems at once: the United States tax system and the United Kingdom tax system. Each has its own rules, filing requirements, deadlines, definitions and reporting obligations.
Whether you are employed in London, self-employed in the UK, running a business, receiving investment income, renting property, or planning a long-term move, it is important to understand your tax position properly.
Good tax awareness can help you avoid missed filings, unexpected penalties, double taxation concerns and unnecessary stress.
Why American Expats Need to Think About UK Tax
The UK tax system can apply to American expats in several ways. If you live in the UK, work in the UK, own UK property, earn UK-source income, or become UK tax resident, HMRC may expect you to report income, gains or other financial activity.
Some American expats assume that because they are US citizens, their main tax responsibility is only to the IRS. Others assume that if they pay UK tax, they no longer need to file anything in the United States. Both assumptions can be dangerous.
The reality is that your tax obligations depend on your personal circumstances. Your residence status, income sources, employment arrangement, bank accounts, investments, business interests, pension arrangements and family situation may all affect what needs to be reported.
For this reason, American expats in the UK should not rely on guesswork. The interaction between HMRC and IRS requirements needs careful attention.
UK Tax Residence
One of the most important starting points is UK tax residence. The UK has a specific system for deciding whether someone is resident for tax purposes. This is known as the Statutory Residence Test.
Your UK tax residence position can affect whether you pay UK tax on UK income only or whether foreign income and gains may also need to be considered. The number of days you spend in the UK is important, but it is not the only factor. Work, accommodation, family and other ties may also be relevant.
This is particularly important for American expats who travel regularly, move part-way through the year, retain a home in the United States, work remotely, or have income in more than one country.
The UK tax year runs from 6 April to 5 April. This is different from the US calendar tax year, which can make filing and tax planning more complicated for Americans.
UK Tax on Employment Income
Many American expats in the UK are employees. If you work for a UK employer, income tax and National Insurance may be deducted through PAYE. This can make the UK side of your employment tax position appear straightforward.
However, PAYE does not automatically deal with every tax requirement. You may still need to complete a UK Self Assessment tax return if you have additional income, foreign income, rental income, capital gains, self-employment income, directorship income or other reportable matters.
You should also remember that UK employment income may still need to be reported on your US tax return. The fact that your salary has been taxed in the UK does not automatically mean it can be ignored for US purposes.
UK Self Assessment
Self Assessment is HMRC’s system for collecting tax from individuals whose full tax position is not dealt with automatically through PAYE.
American expats may need to file a UK Self Assessment tax return if they are self-employed, a partner in a business partnership, a landlord, a company director, have capital gains, receive untaxed income, or have other circumstances that require reporting.
For American expats, UK Self Assessment should be considered alongside US tax filing. The same income may need to be reviewed under both systems, but the calculations and tax treatment may not be identical.
This is one reason why cross-border tax advice is so important. Filing in one country without considering the other can create inconsistencies or missed opportunities for tax relief.
UK Tax on Foreign Income and Gains
American expats often retain financial connections to the United States. These may include US bank accounts, brokerage accounts, pensions, retirement accounts, stock options, rental properties, business interests or family trusts.
If you are UK tax resident, foreign income and gains may need to be considered for UK tax purposes. This can include income from overseas employment, rental income, dividends, interest, pensions and capital gains.
The treatment will depend on your residence position, the source of income, the type of asset, the tax year involved and any relevant reliefs. This area can be especially complex for American expats because US tax treatment and UK tax treatment may differ.
For example, a US investment that appears tax-efficient from a US perspective may not be treated the same way in the UK. Similarly, the sale of an asset may produce different calculations under US and UK tax rules.
US Tax Obligations Do Not Automatically Disappear
American expats should also remember that the US generally continues to tax its citizens and resident aliens on worldwide income, even when they live abroad.
This means a US citizen living in the UK may still need to file a US federal tax return. Depending on their circumstances, they may also need to consider state tax, foreign account reporting, foreign asset reporting and other IRS forms.
This can surprise American expats who have lived in the UK for many years and assumed that they no longer had US filing obligations. In many cases, the obligation to file may remain even if no US tax is ultimately due after foreign tax credits or other reliefs are applied.
Foreign Tax Credits and Double Taxation
One of the biggest concerns for American expats is double taxation. Nobody wants to pay tax twice on the same income.
The US and UK systems include mechanisms that may reduce the risk of double taxation, including Foreign Tax Credits and treaty-based provisions. However, these mechanisms need to be used correctly.
The UK may tax income in one way, while the US may classify or calculate that same income differently. Timing differences, exchange rates, deductions, credits and reliefs can all affect the outcome.
This is why it is important to prepare US and UK tax filings in a coordinated way. The aim should be to comply with both systems while reducing unnecessary double taxation where lawful relief is available.
FBAR and Foreign Account Reporting
US expats in the UK should also be aware of foreign account reporting requirements. Ordinary UK bank accounts may be considered foreign accounts for US reporting purposes.
If the combined value of foreign financial accounts exceeds the relevant threshold at any point during the calendar year, an FBAR filing may be required. This can apply even if the accounts are not generating income and even if no additional US tax is owed.
Accounts that may need to be reviewed include UK current accounts, savings accounts, investment accounts and certain other financial accounts.
FBAR is one of the areas most commonly overlooked by American expats. The penalties for non-compliance can be serious, so it is important to take advice if you are unsure whether the rules apply to you.
Property, Investments and Pensions
American expats in the UK should also take care when dealing with property, investments and pensions.
Buying or selling UK property may create UK tax reporting requirements. Selling US property while living in the UK may also have UK tax implications. Investment portfolios can create income, gains and reporting issues in both countries.
Pensions and retirement accounts can be particularly complex. A pension arrangement that is familiar in the United States may need special consideration in the UK. Equally, UK pension contributions or withdrawals may have US tax consequences.
Before making major financial decisions, American expats should consider whether both HMRC and IRS rules have been reviewed.
Common Mistakes American Expats Make
Common mistakes include assuming that UK tax replaces US tax, ignoring US filing obligations, missing FBAR filings, failing to register for UK Self Assessment, misunderstanding UK tax residence, selling assets without tax advice, failing to report foreign income, and using an adviser who only understands one tax system.
Another common mistake is waiting until there is a problem. Cross-border tax issues are often easier to manage when advice is taken early. Once deadlines have passed or returns have been filed incorrectly, the process can become more stressful and expensive.
Why Specialist US/UK Tax Advice Matters
American expats in the UK need tax advice that understands both sides of the Atlantic. UK-only advice may miss IRS obligations. US-only advice may miss HMRC requirements.
A specialist US/UK tax adviser can help identify filing obligations, review residence status, prepare US federal and state tax returns, handle UK Self Assessment, advise on FBAR, consider Foreign Tax Credits, review foreign income and gains, and provide practical guidance for expats with cross-border financial lives.
Tax compliance should not be treated as an afterthought. For American expats, good advice can provide clarity, reduce risk and help ensure both HMRC and IRS obligations are properly managed.
Contact Xerxes Associates LLP
If you are an American expat living, working or investing in the UK, Xerxes Associates LLP can help you understand your tax obligations.
Xerxes Associates LLP is a London-based firm of specialist US and UK tax advisers. The firm provides tax advice and accountancy services for US and UK expats, including US federal and state income tax returns, UK Self Assessment tax returns, personal tax planning, consultations, FBAR assistance and ITIN support.
To discuss your circumstances, contact Xerxes Associates LLP using the details below:
Xerxes Associates LLP
Warnford Court
29 Throgmorton Street
London
EC2N 2AT
United Kingdom
Telephone: +44 (0)207 411 9026
Alternative Number: +44 (0)207 411 9051
Email: info@xerxesllp.com
Website: xerxesllp.com
If you are unsure whether you have UK tax obligations, US tax obligations, or both, it is better to seek specialist advice before a filing issue arises.
