Navigating Tax Efficient Investing After UK Non-Dom Reform

Written by Dan Keeley

Navigating Tax Efficient Investing After UK Non-Dom Reform

As a US taxpayer living in the UK, managing your financial affairs across two tax jurisdictions often brings additional complexity and margin for error. With the recent changes to the UK’s non-domiciled regime (effective from 6^th April 2025), long-term residents need to be aware of how these changes impact them.

In summary, individuals who have been UK tax residents for more than four UK tax years are now subject to UK taxation on their worldwide income and gains. The ability to claim the remittance basis is no longer available, meaning assets once held offshore from a UK perspective may now come into scope of HMRC.

This development presents a unique challenge, requiring investments to be aligned with both US and UK tax systems. Failure to plan effectively could result in unnecessary tax exposure, increased compliance costs, and compromised long-term financial outcomes.

Understanding the Dual Tax Exposure

The US Perspective: Passive Foreign Investment Companies

Passive Foreign Investment Companies, or PFICs, represent a major tax concern for Americans abroad. These include many common UK investment products such as Open-Ended Investment Companies (OEICs), Unit Trusts, ETFs, investment bonds, EIS (Enterprise Investment Schemes) and VCTs (Venture Capital Trusts) investments.

Under US tax law, PFICs face:

• Taxation at the highest marginal tax rate regardless of your actual income bracket
• Interest charges on deferred gains
• Mandatory annual reporting using Form 8621

Investors in PFICs are often subject to a combination of punitive taxation and administrative burden that erodes after tax returns.

The UK Perspective: Funds Without Reporting Status

In the UK, investment funds that do not have UK reporting status are treated unfavourably:

• Gains are taxed as offshore income gains rather than capital gains
• These are taxed at your marginal income tax rate which may be as high as 45%
• The UK capital gains annual exemption does not apply

This can result in significantly higher UK tax charges than many investors expect.

The ISA Trap for US Taxpayers

While Individual Savings Accounts are popular tax efficient vehicles in the UK they are not recognised as such by the US Internal Revenue Service.

From a US tax perspective:

• ISAs are treated as regular taxable accounts
• Dividends interest and gains are both reportable and taxable in the US
• Non-US funds held within ISAs may trigger PFIC treatment

Careful selection of investments inside an ISA is therefore essential for US taxpayers living in the UK.

Strategic Investment Approaches

Option One: Direct Ownership of Individual Securities

Some investors attempt to avoid the complexities of fund structures altogether by holding individual stocks and bonds. This approach can successfully avoid both PFIC and non-reporting fund classifications. However, it also brings with it a number of trade-offs in terms of performance risk diversification and tax complexity.

 

Benefits	Considerations
Avoids PFIC classification under US tax law	Increased risk of underperformance relative to diversified portfolios
Avoids non reporting fund status in the UK	Limited diversification and higher concentration risk
Greater control with including, or excluding, certain companies from your investment portfolio	Cross border tax reporting complexity for income and capital gains
Can reduce structural costs for long term holders	Requires active portfolio management and ongoing monitoring

 

While suitable in specific circumstances direct security ownership is rarely an optimal strategy for long term diversified wealth accumulation.

Option Two: US Domiciled Funds with UK Reporting Fund Status

A more efficient and scalable approach involves investing in US domiciled mutual funds and ETFs that have obtained UK reporting fund status. This structure avoids both PFIC classification and non-reporting fund treatment while offering access to globally diversified portfolios.

Advantages of this approach include

• Alignment with both US and UK tax regimes
• Access to global diversification across asset classes and geographies
• Efficient custody and trading costs using US investment platforms
• Reduced administrative burden and simplified tax reporting

For US taxpayers in the UK this solution offers a practical framework for long term tax efficient investing.

Post Reform Planning: Navigating the End of the Remittance Basis

In light of the sweeping legislative changes, the investment landscape for US taxpayers residing in the UK has undergone a fundamental shift. Holding assets offshore (from a UK perspective) may no longer be out of scope for UK taxes and therefore a detailed review on the tax efficiency of your investment holdings should be prioritised.

For US connected individuals, this change amplifies the importance of robust cross border planning. The interplay between UK tax rules and US PFIC regulations creates a high risk of unnecessary tax drag and reporting complexity.

If you haven’t done so already, now is the time to review and restructure your investments to ensure they are aligned with the new reality. Taking proactive steps today can help protect your capital, reduce long term tax liabilities, and ensure ongoing compliance across both jurisdictions.

Risk Warnings:

• All investments involve risk and may lose value.  The value of your investment can go down depending upon market conditions and you may not get back the original amount invested.
• Your capital is always at risk.
• Nothing in this document constitutes investment, tax or any other type of advice and should not be construed as such.
• MASECO is not a tax specialist and we recommend that anyone considering investing seeks their own tax advice.
• The tax treatment depends on the individual circumstances of each individual and may be subject to change in the future.
• Past performance is not a reliable indicator of future results.

MASECO LLP (trading as MASECO Private Wealth and MASECO Institutional) is established as a limited liability partnership under the laws of England and Wales (Companies House No. OC337650) and has its registered office at The Kodak Building, 11 Keeley Street, London, WC2B 4BA.  For your protection and for training and monitoring purposes, calls are usually recorded.

MASECO LLP is authorised and regulated by the Financial Conduct Authority for the conduct of investment business in the UK and is registered with the US Securities and Exchange Commission as a Registered Investment Advisor.