Do US citizens living in the UK have to file a US tax return?
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Yes — for as long as you hold US citizenship or a green card, you file a US federal return on your worldwide income no matter where you live. Moving to the UK does not switch that off; it simply adds UK residence taxation alongside it. The two are then reconciled through the treaty and the Foreign Tax Credit, which is the work a specialist actually does.
Do I have to pay tax twice as a US-UK dual citizen?
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In practice, no, provided the returns are prepared together. Relief for the tax paid in one country is given against the tax due in the other, so the same income is not taxed twice over. Double taxation is a symptom of returns prepared in isolation, not an inherent feature of holding both nationalities.
Does becoming a British citizen change my US tax filing obligations?
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No. Acquiring UK citizenship has no effect on your US obligations — the US taxes by citizenship, so you continue to file US returns until you formally renounce, which is a separate and consequential legal step. Naturalising in Britain adds rights here; it removes nothing on the US side.
Do I also need to file a UK Self Assessment return?
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If you are UK resident with foreign income, self-employment, rental income, or capital gains — or HMRC asks you to — then yes. Residence itself is decided by the Statutory Residence Test. A specialist runs that test first, because the answer determines the whole shape of your UK return and how it dovetails with the US one.
I'm an accidental American — do I still have to file with the IRS?
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Yes. If you were born in the US or acquired citizenship through a parent, you are a US taxpayer even if you have never lived there. Many accidental Americans discover this through a FATCA letter from their bank. The Streamlined Filing route exists precisely to bring non-wilful accidental Americans into compliance without penalties.
Do green-card holders in the UK have the same obligations as citizens?
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Broadly yes — a lawful permanent resident is taxed on worldwide income like a citizen, even while living in the UK, until the green card is formally abandoned. There can also be exit-tax consequences on giving it up after long-term residence, so the timing and the paperwork both matter.
How does the US-UK tax treaty prevent double taxation?
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The treaty allocates taxing rights between the two countries and, together with the Foreign Tax Credit, ensures tax paid in one is credited against tax due in the other. It also sets rules for specific income — pensions, dividends, interest, government service — and provides tie-breakers where both countries would otherwise call you resident.
What is the treaty saving clause and how does it affect me?
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The saving clause lets the United States tax its citizens as if most of the treaty did not apply to them. The practical effect is that a US citizen cannot use the treaty to escape US filing or to claim UK-only residence against the IRS; the treaty reduces and re-sources your tax, but the US return remains. Specialists work within the exceptions the clause itself allows.
How do the tie-breaker rules decide where I'm resident?
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When both countries consider you resident, the treaty's tie-breaker tests apply in order — permanent home, then centre of vital interests, then habitual abode, then nationality — to assign a single treaty residence. This matters for non-US-citizens especially; for US citizens the saving clause limits its effect, but it still governs specific income and can be decisive for green-card holders.
Which country taxes my income first if I live in the UK?
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Generally the UK, as your country of residence, taxes your UK and worldwide income first, and the US then gives a Foreign Tax Credit for the UK tax on the same income. That ordering is why a specialist settles the UK figures before finalising the US return — the credit depends on them.
What's the difference between the Foreign Tax Credit and the Foreign Earned Income Exclusion?
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The exclusion (Form 2555) removes a set band of earned income from US tax; the credit (Form 1116) offsets the foreign tax you have already paid against your US bill. For most people in the higher-taxed UK the credit is stronger and generates carry-forwards, while the exclusion can suit lower-taxed or specific cases. The choice is not permanent-free, so a specialist models it rather than assuming.
Is there a US-UK totalization agreement for Social Security and National Insurance?
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Yes. The US-UK totalization agreement stops you paying into both social-security systems on the same earnings and determines which country's system you contribute to, typically based on where and for whom you work. It also helps protect benefit entitlement across a career split between the two countries. It is a frequently missed saving for secondees and the self-employed.
How does the UK Statutory Residence Test decide if I'm UK resident?
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The Statutory Residence Test weighs the number of days you spend in the UK against connecting ties — accommodation, family, work and time spent here in prior years — through automatic and sufficient-ties tests. It gives a definitive answer rather than a judgement call, which is why we apply it at the outset of every engagement.
What replaced the non-dom remittance basis in 2025?
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From 6 April 2025 the UK abolished the remittance basis for non-domiciled residents and moved to a residence-based system. New arrivals may instead use a four-year Foreign Income and Gains regime. If you previously relied on non-dom treatment, or have recently become UK resident, your position — and its interaction with your US credits — has changed materially.
How does the 4-year FIG regime work for new UK arrivals?
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The Foreign Income and Gains regime can exempt qualifying foreign income and gains from UK tax for the first four years of UK residence for those who qualify, replacing the old remittance basis. For a US citizen it needs careful coordination: income exempt in the UK still faces US tax, and exempting UK tax can reduce the Foreign Tax Credit available, so the planning has to look at both sides together.
Are UK ISAs taxable in the US, and are they PFICs?
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Yes on both counts, usually. An ISA is tax-free to HMRC but its income is taxable to the IRS, and the funds inside a stocks-and-shares ISA are typically PFICs reported on Form 8621. The UK's flagship tax-free savings wrapper is, unfortunately, one of the more troublesome things a US taxpayer can hold — which a specialist will tell you before you keep contributing.
How are UK pensions (SIPP and workplace) treated on my US return?
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The treaty generally allows UK pensions to grow without current US tax and taxes most pension income in your country of residence, with particular rules for lump sums. The UK 25 percent tax-free lump sum is not automatically tax-free to the IRS, and SIPPs, workplace schemes and the State Pension each behave differently, so pensions are a specialist-level area rather than a checkbox.
Do PFIC rules apply to my UK investment funds?
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Almost always. Non-US pooled investments — UK OEICs, unit trusts, investment trusts and ETFs — are Passive Foreign Investment Companies to the IRS, taxed under a punitive default regime unless a timely election is made, and reported per fund on Form 8621. Identifying PFICs and choosing the right election is one of the clearest reasons to use a specialist rather than software.
How is UK rental property income taxed on both returns?
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It is reported on both the UK and US returns, with a Foreign Tax Credit for the UK tax preventing double taxation. The taxable profit differs between the two systems because US rules require depreciation and allow a different set of expenses, so the numbers rarely match and each return must be computed on its own basis.
Do I pay US tax when I sell my UK main residence?
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You might. The UK's Private Residence Relief can exempt the whole gain, but the US only excludes up to 250,000 dollars (500,000 for a married couple filing jointly) and taxes the excess. A substantial gain on a long-held London home can therefore produce a US bill with no matching UK tax to credit — and a separate currency gain can arise on any mortgage repaid along the way.
What is FBAR and do I need to file it?
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The FBAR (FinCEN Form 114) discloses your non-US financial accounts to the US Treasury when their combined peak balance exceeds 10,000 dollars in the year. Most UK residents cross that line once accounts, savings, ISAs and pensions are totalled. It is filed separately from your tax return and carries serious penalties if overlooked, so it is a fixture of every cross-border engagement.
What is FATCA / Form 8938, and how is it different from FBAR?
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FATCA's Form 8938 reports specified foreign financial assets on your tax return, with higher thresholds than the FBAR and a partly different scope — it captures some assets the FBAR does not, and vice versa. Many US persons in the UK must file both, and a specialist ensures the two are consistent rather than contradictory.
When do I need Form 5471 for my UK company?
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If you are a US person who owns or controls a UK company — broadly, holding 10 percent or more, with control at 50 percent — you generally must file Form 5471, and the controlled-foreign-corporation rules can pull the company's profits onto your US return through GILTI and Subpart F. It is among the most technical filings in cross-border tax and central to our founder and business work.
What are the Streamlined Filing Compliance Procedures?
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They are the IRS's designated route for taxpayers whose failure to file was non-wilful. Americans abroad use the Foreign Offshore version: three years of returns, six years of FBARs and a certification of non-wilfulness, with a 0 percent offshore penalty for those who qualify. It is available only until the IRS makes contact, so acting early preserves the outcome.
I haven't filed for years — how do I get caught up without penalties?
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For most non-wilful taxpayers abroad, the Streamlined Foreign Offshore Procedures achieve exactly that: full compliance with no penalties, paying only the actual tax due plus interest across the covered years. The key is coming forward before the IRS contacts you and preparing a complete, internally consistent submission — which is what we do routinely.
What happens if I've missed FBARs?
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Missed FBARs are usually folded into a Streamlined submission, which covers six years of FBARs and removes the penalties for non-wilful filers. Filing back FBARs quietly, outside a recognised procedure, forfeits that protection, so the route you choose matters as much as the forms themselves.
What makes a US-UK tax specialist different from a regular accountant?
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A specialist prepares and optimises both returns and sees how each affects the other — the credit ordering, the treaty positions, the PFIC and Form 5471 exposures — whereas a general accountant is qualified on one side only and expat software automates neither well. The difference shows up as a lower correct tax figure and a submission that survives scrutiny, not just a completed form.
How much does US and UK tax return preparation cost?
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We agree a fixed, scoped fee before starting, sized to the returns and forms your circumstances need. A simple employed dual filer costs considerably less than a founder with a UK company, PFIC holdings and property. The quote covers both returns and the specific international forms, so there are no hourly surprises later.
Should I use a CPA or an Enrolled Agent — and can one firm file both returns?
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Both a CPA and an IRS Enrolled Agent are fully authorised to prepare US returns and represent you before the IRS, so either is fine on the US side; what matters is genuine cross-border experience. The UK side should be handled by an ACA, ACCA or CTA-qualified accountant. A true specialist firm holds both capabilities in-house and files both returns together, which is the point.
What are the US and UK tax filing deadlines?
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The UK tax year ends on 5 April, with online Self Assessment due by 31 January. The US uses the calendar year: returns are due 15 April, automatically extended to 15 June for Americans abroad and to 15 October on request, with the FBAR following the return to a 15 October extension. Coordinating the two calendars is part of a specialist's job.
Can you handle everything from abroad, and what do you need to start?
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Yes — we work with clients across the UK, the US and beyond entirely remotely. To begin we need your prior US and UK returns, income documents (P60s, payslips, W-2s, 1099s), account statements for FBAR purposes, pension and investment paperwork, and details of any property or company. You receive a precise checklist so nothing is gathered twice.
