Tax help for British citizens with US income, assets or family
You do not need a US passport to have a US tax problem. A rental in Florida, an old Green Card, a US brokerage account or an American spouse can each pull a British taxpayer into the IRS system — while HMRC still expects its full share.
Last reviewed 1 September 2026 · 2 min read
This guide applies to you if:
- You are a UK resident with US rental property, investments or work income
- You hold, or once held, a US Green Card
- You are married to a US citizen, or inherit or hold assets in the US
Your situation
You are British, you live in the UK, and America has crept into your finances anyway. Perhaps you worked in the States and left a 401(k) or a brokerage account behind. Perhaps you bought a holiday rental in Florida, married an American, inherited US assets, or still hold a Green Card from a chapter you thought was closed. Each of these creates real obligations on the US side — alongside everything HMRC already expects.
What each country expects from you
The United Kingdom taxes you, as a resident, on your worldwide income and gains — US rent, US dividends, US pension income included. Anything not taxed through PAYE generally goes on Self Assessment, due online by 31 January.
The United States taxes by source and by status. US rental income, US business income and gains on US real estate are taxable there even for non-Americans, usually via a nonresident return, sometimes with state filings on top. Hold a Green Card, and the US treats you as a full tax resident on worldwide income until the card is properly given up. Married to a US citizen, and the household faces filing-status decisions with long consequences — notably, a US citizen filing separately must file with income of just $5, and electing to file jointly would sweep your own worldwide income into the US net.
The US–UK treaty allocates taxing rights between the two countries and is what prevents most double taxation — but it works only when both returns are prepared with it in mind.
The classic traps
- US funds without UK reporting status. Many US-domiciled funds and ETFs are non-reporting offshore funds to HMRC, so gains are taxed as income rather than capital gains.
- US LLCs. HMRC and the IRS can characterise the same LLC differently, and the mismatch can mean tax on both sides with no relief. See US LLCs for UK residents.
- The forgotten Green Card. US tax residence does not lapse just because you moved home.
- Joint finances with an American spouse. Joint accounts and jointly owned assets flow into their US reporting, and casual filing choices can be costly to unwind.
- US withholding left on autopilot. The treaty often reduces US withholding on dividends, interest and pensions — but only if the right forms are in place.
One firm, both returns
Cross-border problems rarely respect the boundary between a UK accountant's job and a US preparer's job. We prepare UK Self Assessment and US returns under one roof, so treaty positions, credits and entity questions are answered once and reflected consistently on both sides. Fixed fees are agreed before work begins.
When to get advice
Get advice before selling US property or US funds, before making any US filing election with your spouse, and before abandoning a Green Card — order of operations matters in all three. If you suspect an obligation has already been missed, earlier is cheaper than later. Contact us and we will map exactly what the US side requires of you.
Frequently asked questions
I own a US rental property. Do I file in America, the UK, or both?
Usually both. The US taxes rental income from US property even when the owner lives abroad, typically via a nonresident return, and some states add their own filing. The UK then taxes the same income as part of your worldwide income, with credit generally available for the US tax paid.
My spouse is American. Does that affect my UK taxes?
Your UK position barely changes, but the household's US position can change a lot. Your spouse faces US filing choices that affect joint accounts, jointly owned property and investments, and electing to file jointly with them would bring your worldwide income into the US system. These choices deserve advice before, not after.
I have a Green Card but moved back to Britain years ago. Am I done with the IRS?
Not automatically. Green Card holders generally remain US tax residents until the card is formally abandoned, however long they have been outside the US. Many returnees have ongoing US filing obligations they are unaware of, and the exit itself has tax consequences worth planning.
Are my US funds and ETFs a problem in the UK?
They can be. Gains on offshore funds without UK reporting fund status are taxed as income rather than capital gains, which is usually a worse outcome. Checking the status of each holding before selling is one of the simplest pieces of cross-border hygiene.
Sources & further reading
This page provides general information about US and UK tax rules. It is not personalised tax advice, and rules change — always take professional advice on your own circumstances before acting. Content last reviewed on 1 September 2026.
Related guides
The US–UK Tax Treaty in Practice: What It Does and Does Not Do
How the 2001 US–UK income tax treaty allocates taxing rights, why the saving clause limits it for US citizens, where it genuinely helps — pensions, Social Security, dividends, tie-breakers — and when Form 8833 disclosure is needed.
Learn moreUS LLCs Owned by UK Residents: The Mismatch That Taxes Profits Twice
Why a US LLC that works perfectly for Americans can misfire for a UK resident: US pass-through treatment versus HMRC's opaque-entity view, the Anson case, double-tax risk, and when a different vehicle is the better answer.
Learn moreGreen Card Holders
A Green Card makes you a US tax resident wherever you live — including in the UK. What the IRS still expects, how UK residence layers on top, the treaty and expatriation pitfalls, and how to keep or surrender the card without a tax mess.
Learn moreProperty Across the Atlantic: Buying, Letting and Selling in Two Tax Systems
Cross-border property for US–UK taxpayers: rental income reported to both countries, currency gains on sale and on mortgage redemption, the UK's 60-day CGT reporting against annual US reporting, and the main-residence relief mismatch.
Learn moreUnsure how this applies to you?
Every cross-border situation is different. A consultation maps the rules onto your facts — before deadlines or elections make choices for you.
Or call +44 20 8064 3580 — we’ll tell you honestly whether you need help.