US Expat Tax Services for Americans Living in the UK
Americans living in the UK face a tax system that follows them wherever they go. The United States is one of only two countries that taxes its citizens on worldwide income regardless of where they live. That single rule shapes every financial decision an American expat makes once they cross the Atlantic. For hedge fund managers, fund partners, and other high earners, the stakes get sharper. Carried interest, deferred compensation, and offshore investment structures create reporting obligations on both sides of the ocean, and a single misstep can trigger penalties that dwarf the underlying tax bill. Specialist US Expat Tax Services exist precisely because the cost of getting this wrong is rarely small.
This guide explains what these services cover, why 2026 has raised the bar for compliance, and how a London-based hedge fund manager should think about their dual tax exposure. It draws on the kind of work we handle every week at Jungle Tax for American clients in finance, law, and entrepreneurship.
What Are US Expat Tax Services?
US Expat Tax Services are specialist advisory and compliance services for Americans living outside the United States. They cover annual federal tax return preparation (Form 1040), foreign bank account reporting (FBAR), FATCA disclosures, tax treaty positions, foreign tax credit calculations, state tax disengagement, and planning around items unique to expats such as the Foreign Earned Income Exclusion, the GILTI regime for owners of foreign companies, and PFIC rules for non-US investment funds.
For an American in the UK, the work also involves HMRC. UK residents pay UK tax on their worldwide income once the remittance basis is no longer claimed, and the changes introduced from April 2025 have removed the old non-domiciled regime in favor of a residence-based system. That shift, explained in detail by https://www.gov.uk/government/publications/changes-to-the-taxation-of-non-uk-domiciled-individuals , has rewritten the planning playbook for almost every American who arrived in the UK before 2025.
Why US Expat Tax Services Matter More in 2026
The compliance environment has tightened on both sides. The IRS has expanded data sharing under FATCA, meaning UK banks and investment platforms routinely report American account holders to the US Treasury. HMRC, meanwhile, exchanges information with the IRS under the https://www.gov.uk/government/publications/uk-us-automatic-exchange-of-information-agreement, so income that appears on one side almost always surfaces on the other.
Three forces make 2026 particularly demanding for American expats. First, the abolition of UK non-dom status means the remittance basis no longer shields foreign income for long-term UK residents, so US-source dividends, partnership distributions, and capital gains are now fully exposed to UK tax in most cases. Second, IRS enforcement against high earners has grown sharper, with the agency publicly committing additional resources to wealthy individuals and complex partnerships. Third, the carried interest rules in the UK shifted again in April 2025, moving carried interest into the income tax framework at a 32% rate for most fund managers, which changes the foreign tax credit arithmetic on the US side.
Anyone running personal finances across two tax systems without specialist help is now operating with a level of risk that was uncommon even five years ago.
Core Components of US Expat Tax Services for HNW Clients
Dual Filing and Treaty Coordination
Every American citizen with income above the filing threshold must file a US tax return, and every UK tax resident must report worldwide income to HMRC. The two returns interact through the US-UK tax treaty and the foreign tax credit system. The job of an expat tax adviser is to make sure income is taxed at the higher of the two rates, never twice, and that the credits flow in the correct direction. For finance professionals with bonus deferrals, restricted stock, and partnership income, the matching exercise across two tax years (the US calendar year and the UK 6 April year) is where most preventable errors occur.
Reporting Foreign Accounts and Investments
Americans holding more than $10,000 across non-US accounts at any point during the year must file an FBAR with FinCEN, and most must also file Form 8938 with their tax return. The thresholds, due dates, and penalties are explained in https://www.irs.gov/businesses/comparison-of-form-8938-and-fbar-requirements . For hedge fund managers, the reportable accounts often extend beyond personal banking to include management company accounts, GP vehicle accounts, and any signature authority over fund accounts, which catches many people by surprise.
Investment Structuring Around PFIC and GILTI
UK-domiciled funds, OEICs, and most non-US ETFs are classified as Passive Foreign Investment Companies under US rules, and the default tax treatment is punitive. Owning a UK-listed fund in an ISA does not solve the problem, as the IRS does not recognize ISAs as tax-advantaged. Specialist US Expat Tax Services help clients restructure portfolios into US-compliant holdings or make qualifying elections where possible. Hedge fund partners with personal stakes in non-US management companies also need to consider GILTI, which can pull operating income into their personal US returns at unexpected rates.
How a Hedge Fund Manager Should Approach US Expat Tax Filing
Map every income stream first. Before any numbers are entered, list every source: base salary, cash bonus, deferred bonus, carried interest accruals, carried interest distributions, management fee allocations, co-investment gains, personal portfolio income, and any UK rental or dividend income. Without a clean map, treaty positions and credits cannot be set up correctly.
Reconcile UK and US tax years. The UK runs from 6 April to 5 April; the US runs from January to 31 December. Income earned in the overlap months will appear in two different UK tax years and one US tax year, and the foreign tax credit must be sourced to the correct year on each side.
Decide on the carried interest treatment. Under the post-April 2025 UK rules, carried interest is taxed at 32% as income for most fund managers, with further reforms from April 2026 that layer on additional rules for non-residents. The US continues to treat qualifying carried interest as long-term capital gain after a three-year holding period. The mismatch creates both planning opportunities and timing traps, which is why this is the single most important conversation a hedge fund manager should have with a cross-border adviser each year.
Document FBAR and FATCA exposure. Pull statements for every account with signature authority or beneficial ownership, including GP vehicles, escrow accounts, and any trust accounts. Aggregate the highest balance for the year per account, not the year-end balance.
Plan estimated payments on both sides. US payments are due quarterly, UK payments on account are due in January and July. Cash-flow planning for high-bonus years is part of the service, not an afterthought.
Review state tax exposure. Many American expats believe leaving the US ends state tax obligations, but California, New York, and a handful of other states apply aggressive residency tests. Properly severing state ties is part of a clean expat tax position.
Case Study: An American Hedge Fund Manager Relocating to London
A US citizen working as a portfolio manager at a New York hedge fund accepted a senior role with the firm’s London affiliate in early 2024. His package included a base salary of around £400,000, an annual cash bonus targeting £600,000, deferred equity that vested over three years, and an allocation in the GP of a new long-short fund the London office was launching. He had a New York co-op he intended to keep, two children in private school in London, and a portfolio mixing US ETFs with a UK ISA his wife had opened before they understood the implications.
The first year of work focused on stabilizing compliance. We filed his US return, claiming foreign tax credits against UK income tax on his salary and bonus; prepared FBARs for every UK account he and his wife held; and filed Form 8938 for accounts above the higher threshold. The UK ISA holdings were identified as PFICs, and we modeled the cost of liquidating them against the cost of QEF or mark-to-market elections. Liquidation was the cleaner answer in his case.
The harder work was structural. His GP’s interest in the new fund required careful US characterization, partly to preserve eventual long-term capital gain treatment on carried interest under US rules and partly to avoid GILTI exposure for the management company. We coordinated with the firm’s UK tax counsel so that the partnership documentation worked under both systems. On the New York co-op, we set up a clean foreign tax credit position for rental income and confirmed that, given his factual ties, New York State could no longer assert residency. By year two, his effective combined rate was within two percentage points of what a clean UK-only filing would have produced, the lowest legitimately achievable outcome in his situation.
Common Mistakes American Expats Make
Ignoring the PFIC rules on UK funds. Buying a UK-domiciled fund or ETF without a PFIC analysis is the single most common and most expensive mistake. The default tax treatment can absorb most of the gain, and the reporting is onerous. Stick to US-listed funds in taxable accounts unless an adviser has confirmed a workable election.
Treating the ISA as tax-free on the US side. ISAs are not recognized by the IRS. Dividends and gains inside an ISA are fully taxable in the US, and the underlying holdings often trigger PFIC reporting.
Filing only on one side. Some expats file in the UK and assume the US return can wait. Late US filings carry penalties even when no tax is due, and Streamlined Filing Compliance Procedures are available only to taxpayers whose non-compliance was non-wilful.
Missing FBAR accounts with signature authority. Hedge fund managers often have signing power over fund or GP accounts that they do not personally own. Those accounts are still FBAR-reportable, and the omission is one HMRC and the IRS both look for.
Mishandling carried interest timing. Reporting carried interest in the wrong year on either side of the transaction breaks the foreign tax credit position and is hard to unwind. Each accrual and distribution needs its own treatment.
Assuming the US-UK tax treaty solves everything. The treaty is a powerful tool, but it does not override US citizenship-based taxation, and it does not cover every type of income. Treaty positions must be claimed correctly on the right forms, with disclosure where required.
How Jungle Tax Helps American Expats in the UK
Jungle Tax works with American expats across finance, technology, law, and entrepreneurship, with a particular focus on hedge fund and private equity professionals whose compensation structures sit at the most demanding end of cross-border tax. Our team includes advisers qualified in both UK and US tax, which means a single point of contact handles interactions with the IRS, HMRC, and the treaty between them. We coordinate with fund counsel, wealth managers, and immigration advisers when needed, so the tax position fits inside the wider financial picture rather than sitting on its own. We also handle the operational side of expat life, from state tax disengagement and pre-arrival planning to exit planning for clients returning to the US.
For a confidential conversation about your situation, contact us at hello@jungletax.co.uk.
Conclusion
For Americans in the UK, particularly those earning at the level of hedge fund managers and senior finance professionals, specialist US Expat Tax Services are no longer a convenience. The end of UK non-dom status, the carried interest reforms, sharper IRS enforcement, and the sheer mechanical complexity of running two tax returns in parallel have all raised the cost of getting this wrong. Done well, cross-border tax planning protects income, prevents double taxation, and keeps clients clear of penalties that grow faster than the underlying tax. The right adviser thinks across both systems from the first conversation and keeps thinking that way every year.
