PFICs are only half the story

For many Americans living in the UK, wealth management conversations often begin and end with one topic: avoiding Passive Foreign Investment Companies (PFICs). While PFICs are undoubtedly important, they represent only one piece of a much larger financial planning puzzle.

The reality is that US citizens and Green Card holders living in the UK must navigate two complex tax systems simultaneously. Every financial decision - whether investing, contributing to a pension, purchasing property, receiving income, or planning for retirement - can carry implications under both US and UK tax rules. A strategy that appears tax-efficient in one country may produce unexpected reporting obligations or tax consequences in the other.

Today, Cindy He and Tahir Mahmood look at the 10 things you need to be aware of as an American living in the UK:

1. Investment management

A US-compliant portfolio is often built using directly held securities rather than pooled investment vehicles that may give rise to PFIC reporting. However, effective investment management for US-connected clients extends well beyond PFIC avoidance. Asset location, investment structure, tax efficiency and the currency in which investments are held can all influence long-term outcomes and should be considered as part of a broader financial strategy.

2. Foreign exchange and tax reporting

Currency movements can create tax consequences that are entirely separate from investment performance. An investment that generates little or no gain in one currency may still result in a taxable gain when calculated under the rules of another. As US taxpayers living in the UK are often required to report transactions to both the IRS and HMRC, understanding the impact of exchange rates on gains, losses and income reporting is an important aspect of cross-border financial planning.

3. US and UK tax compliance

US citizens and Green Card holders remain subject to US tax reporting on their worldwide income, regardless of where they live, and may also have ongoing state tax obligations. Where individuals are resident in the UK, they must also comply with UK tax rules, with their residence status determining the scope of UK taxation. Alongside annual tax returns, US reporting requirements for overseas financial accounts (FBAR Reporting) and assets can carry significant penalties if overlooked.

4. Double tax relief

The UK-US Double Tax Treaty is designed to prevent the same income or gain from being taxed twice. However, applying double tax relief is not always straightforward. Understanding where tax should be paid first, how foreign tax credits operate and how different assets are treated under each tax system is essential. Pension arrangements in particular often require careful consideration, as their tax treatment and reporting obligations can differ significantly between the UK and the US.

5. Cross-border planning

A key aspect of cross-border planning is understanding how one financial decision can affect another. Whether changing residence, selling an investment, receiving overseas income or making pension contributions, each action may have different consequences under UK and US tax rules. Differences between the UK and US tax years, together with the application of the UK-US Double Tax Treaty, can affect the timing of income recognition, gains and tax reporting. Planning ahead helps ensure investment decisions, tax compliance and broader financial objectives remain aligned.

6. Estate and succession planning

For US citizens living in the UK, estate planning often involves navigating both UK Inheritance Tax (IHT) and US estate tax rules. Trusts may also form part of a wider wealth transfer strategy, although the tax treatment of trusts can vary significantly between the two jurisdictions. A structure that works well from a UK perspective may not always produce the same outcome under US rules. Taking a coordinated approach helps ensure succession objectives and tax considerations are evaluated together.

7. Retirement planning

Retirement planning becomes increasingly important as financial priorities evolve, particularly when individuals are subject to more than one tax system. Employer pension schemes, SIPPs and IRAs can all be treated differently under UK and US tax rules. Understanding how contributions, investment growth and future withdrawals are taxed in each jurisdiction can help avoid unexpected tax liabilities and support long-term retirement objectives.

8. Family and legacy planning

Whether making lifetime gifts, funding a child's education or planning how wealth will ultimately pass to future generations, these decisions should be viewed within the context of a broader financial plan. The UK and US apply different rules to gifting, succession and reporting, meaning a transaction that appears straightforward in one jurisdiction can have unexpected implications in the other. This is particularly relevant where family members are resident in different countries. Considering both tax systems from the outset can help avoid unintended consequences and ensure family objectives remain aligned with an overall wealth strategy.

9. Equity compensation and executive remuneration

Many US citizens working in the UK receive remuneration through share incentives, restricted stock units (RSUs), stock options or other forms of deferred compensation. The timing of taxation, reporting requirements and availability of tax relief can differ significantly between the UK and US systems. Understanding the treatment of these arrangements is essential to avoid unexpected tax liabilities and to ensure that executive compensation forms part of an integrated wealth strategy.

10. Liquidity and major life events

Significant life events often create complex financial planning considerations for Americans living in the UK. Purchasing a property, selling a business, receiving an inheritance, exercising share options, or funding a major expenditure (like paying your tax liability) can all trigger tax and reporting obligations across multiple jurisdictions. Reviewing these events in advance allows investment strategy, tax planning and cash flow requirements to be considered together, helping to minimise surprises and ensure that financial resources are available when needed.

The Importance of the right team

At W1M, we have a specialist tax and advanced planning team throughout the year, helping clients understand the wider implications of important financial decisions before they are made. By combining investment management with cross-border tax expertise, we aim to provide a more joined-up approach to wealth management- one that helps clients navigate complexity, make informed decisions and remain focused on their long-term financial goals.

Glossary

Passive Foreign Investment Company (PFIC): A non-US pooled investment, such as a UK mutual fund or ETF. The IRS imposes highly punitive tax rates and complex reporting requirements on these assets.

Directly held securities: Individual stocks and bonds owned directly by an investor rather than through a fund. This strategy is commonly used by American expats to avoid PFIC rules.

Pooled investment vehicles: Investment funds that group capital from multiple investors. For US citizens, these foreign funds usually trigger strict PFIC taxation.

Asset location: The strategic placement of investments across different account types and geographic jurisdictions to minimise global tax exposure.

Foreign Exchange (FX) tax impact: Tax liabilities triggered purely by currency fluctuations. A capital gain or loss can be created in the eyes of the IRS or HMRC simply due to changing exchange rates.

Cross-border tax compliance: The requirement for US citizens and Green Card holders to report their global income, assets, and transactions to both the US (IRS) and the UK (HMRC) simultaneously.