London-Based US Expats and HMRC Requirements
London is one of the most popular cities in the world for international professionals, entrepreneurs, investors and high-net-worth individuals. For US citizens and American expats, moving to London can create excellent career, business and lifestyle opportunities. However, it can also create tax responsibilities that should not be ignored.
Many US expats living in London understand that they may still have responsibilities to the IRS. What is sometimes less clear is how HMRC requirements apply once they become UK resident, work in the UK, own UK assets, receive foreign income, or have investment and business interests.
If you are a US citizen, green card holder or American expat based in London, it is important to understand that your UK tax position may need to be considered alongside your continuing US tax reporting obligations. This is where professional US/UK tax advice can make a major difference.
Why HMRC Requirements Matter for US Expats in London
HMRC is responsible for collecting tax in the UK. If you live, work or conduct business in London, you may fall within the UK tax system depending on your residence status, income sources and personal circumstances.
A common mistake among US expats is assuming that UK tax only applies if they are permanently settled in the UK. In reality, UK tax obligations can arise much sooner than expected. Your time spent in the UK, accommodation, employment, family connections and working pattern can all affect your position.
Another common mistake is assuming that because the United States taxes citizens abroad, the UK position is secondary. That is not the case. If you are UK tax resident or have UK-source income, HMRC may still expect appropriate reporting and payment.
For London-based US expats, the real issue is not simply “US tax or UK tax?” In many cases, the issue is how both systems interact.
Understanding UK Tax Residence
One of the first questions for a US expat in London is whether they are UK tax resident. The UK uses the Statutory Residence Test to determine residence for each tax year.
The UK tax year runs from 6 April to 5 April. This is different from the US tax year, which normally follows the calendar year. This difference alone can create confusion when preparing returns, calculating income periods, matching tax credits and understanding filing deadlines.
The Statutory Residence Test considers several factors. These may include how many days you spend in the UK, whether you work full-time in the UK, whether you have accommodation available, whether you have family in the UK, and whether you have other ties to the country.
For many American expats, UK tax residence is not always obvious. Someone may move to London part-way through the year, travel frequently, work remotely, retain a US home, or have income and assets in more than one country. In these situations, tax residence should be reviewed carefully.
Employment Income and PAYE
Many US expats in London are employed by UK businesses, international firms, financial institutions, technology companies, law firms, consultancies or global organisations. If you are employed in the UK, your employer will usually operate PAYE, which means income tax and National Insurance may be deducted from your salary before you are paid.
For straightforward employees, PAYE may deal with much of the UK employment tax position. However, PAYE does not always mean there is nothing else to do.
You may still need to file a UK Self Assessment tax return if you have additional income, high income, rental income, investment income, capital gains, foreign income, self-employment income, directorship income, or other reporting requirements.
US expats should also remember that employment income taxed in the UK may still need to be reported on a US tax return. The fact that tax has been deducted by HMRC does not automatically remove the IRS reporting requirement.
UK Self Assessment for US Expats
Self Assessment is the system used by HMRC to collect tax from individuals whose tax affairs are not fully dealt with through PAYE.
A US expat in London may need to register for Self Assessment and file a UK tax return if their circumstances require it. This can include situations where they are self-employed, have rental income, receive untaxed income, are a company director, claim certain reliefs, receive foreign income, or have capital gains to report.
For Americans in London, Self Assessment can become more complex because the same income may also need to be considered for US tax purposes. This does not automatically mean tax will be paid twice, but it does mean the reporting must be handled properly.
Foreign Tax Credits, tax treaty provisions and the timing of income recognition may all need to be reviewed carefully.
Foreign Income and HMRC
London-based US expats often have financial connections outside the UK. These may include US bank accounts, investment portfolios, retirement accounts, rental property, business interests, stock options, pensions or trusts.
If you are UK tax resident, foreign income and gains may need to be considered for UK tax purposes. The treatment will depend on your residence status, domicile position, the type of income, whether income or gains are remitted to the UK, and the rules in force for the relevant tax year.
This is an area where generic advice can be risky. A US expat with US investments may have one set of issues. A business owner may have another. A person with US pensions, stock options or property income may require a different approach again.
The important point is that HMRC requirements should be reviewed before assumptions are made.
Capital Gains and Asset Sales
US expats in London should also be careful when selling assets. This may include selling shares, cryptocurrency, property, business interests or investments.
Both the UK and US may have tax rules that apply to capital gains. The calculation methods, reporting dates, reliefs and tax treatment may differ between the two countries. This can create unexpected results if advice is not taken before a sale.
For example, a gain may be calculated differently for UK and US purposes. Exchange rates may also affect the final position. The timing of a sale can matter, especially where the individual has recently arrived in or left the UK.
Before selling major assets, London-based US expats should consider taking professional advice to avoid unnecessary tax complications.
UK and US Double Taxation Concerns
Many American expats worry about being taxed twice. This concern is understandable. However, the US and UK tax systems include mechanisms that may reduce double taxation, including foreign tax credits and treaty-based considerations.
The challenge is that these mechanisms must be used correctly. It is not enough to assume that because tax was paid in the UK, the US position will automatically be correct. Equally, it is not safe to assume that filing in the US means HMRC has no interest.
A coordinated approach is often needed. US and UK tax returns should be prepared with awareness of each other, especially where income, credits, deductions, pensions, investments or gains overlap.
FBAR, FATCA and UK Accounts
US expats living in London often open UK bank accounts, savings accounts and investment accounts. These accounts may create US reporting obligations, even if the accounts are ordinary UK accounts used for everyday living.
The FBAR may be required where the aggregate value of foreign financial accounts exceeds the relevant threshold at any point during the calendar year. FATCA-related reporting may also need to be considered depending on the value and type of foreign financial assets.
This is separate from HMRC reporting, but it is highly relevant to US expats in the UK. A London-based American may therefore need to consider UK tax filing, US tax filing and foreign account reporting at the same time.
Why London-Based US Expats Should Seek Specialist Advice
US expat taxation in London is not only about filing forms. It is about understanding the interaction between HMRC requirements and IRS obligations.
A London-based US expat may need help with UK tax residence, UK Self Assessment, US federal tax returns, US state tax questions, FBAR, FATCA, Foreign Tax Credits, Foreign Earned Income Exclusion, pensions, investments, property, business ownership and capital gains.
Using separate advisers who do not understand the other tax system can lead to gaps, duplication or missed planning opportunities. For this reason, many US expats prefer to work with advisers who understand both US and UK tax compliance.
Contact Xerxes Associates LLP
If you are a US expat living or working in London and need help understanding your HMRC requirements and US tax obligations, Xerxes Associates LLP can assist.
Xerxes Associates LLP is a London-based firm of specialist US and UK tax advisers. The firm provides tax advice and accountancy services for expats living in the United Kingdom and the United States, including US federal and state income tax returns, UK Self Assessment tax returns, FBAR and ITIN assistance, tax consultations, personal tax planning and cross-border tax 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
Fax / Alternative Number: +44 (0)207 411 9051
Email: info@xerxesllp.com
Website: xerxesllp.com
If you are unsure whether HMRC requires you to file a UK tax return, or whether your London-based income and assets create US reporting issues, it is better to seek advice early.
