US-UK Dual Tax Filing for Americans Living in the UK
Americans living in the United Kingdom face one of the world's most complex dual-tax situations. Both the US and UK assert broad taxing rights over their residents and citizens respectively, but a comprehensive tax treaty and the Foreign Tax Credit system prevent true double taxation in most cases. The complexity lies in the detail: UK ISAs are not tax-advantaged under US law, UK pension contributions have different treatment on each side, and certain UK investment vehicles (such as foreign-domiciled ETFs) may trigger PFIC reporting. We provide end-to-end US and UK compliance in one service.
Get started with your filingWho this is for
- ✓ American citizens or green card holders living and working in the United Kingdom
- ✓ US-UK dual nationals with tax obligations in both countries
- ✓ Americans in the UK with UK ISAs, SIPPs, or employer pension schemes
- ✓ US citizens married to UK nationals with complex joint versus separate filing questions
- ✓ Americans who moved to the UK recently and need to establish correct filing positions in both countries
What this filing may involve
Every situation is different. The forms below commonly apply — your specific filing may vary.
- 1 US Form 1040 — with Foreign Tax Credit for UK income tax paid
- 2 UK SA100 — Self Assessment for UK employment or self-employment income
- 3 Form 8833 — US-UK treaty-based return positions
- 4 FinCEN Form 114 (FBAR) — UK bank, ISA, pension, and investment accounts
- 5 Form 8938 — FATCA reporting for UK financial assets
- 6 Form 8621 — PFIC reporting for foreign-domiciled ETFs or mutual funds in the UK
- 7 UK SA109 — for residence status disclosure
Documents usually needed
- 📄 UK P60 from employer
- 📄 UK Self Assessment return or SA302 from prior year
- 📄 UK bank, ISA, and SIPP/pension account statements
- 📄 Any investment account statements showing foreign ETFs or funds
- 📄 Prior year US tax return
- 📄 Passport with travel records
- 📄 Social Security number or ITIN
How Nomadic.Tax works
AI-assisted preparation with licensed professional review — every time.
Tell us about your UK income, accounts, and any treaty positions you have previously taken
Upload UK and US tax documents to your Nomadic.Tax dashboard
Our dual-qualified team prepares coordinated US and UK returns, minimising double taxation
Both returns are reviewed by licensed professionals and filed with the respective authorities
When human review matters
- ⓘ UK ISAs are not US tax-advantaged; income inside an ISA is US-taxable and may involve PFICs if non-US funds are held
- ⓘ UK employer pension contributions have complex treatment — broadly not currently US-taxable under treaty, but must be disclosed
- ⓘ The US-UK treaty 'saving clause' preserves the right of each country to tax its own citizens — the treaty does not eliminate your US filing requirement
[INSERT: customer testimonial, e.g. "American tech worker in London, UK, saved money and stress using Nomadic.Tax"]
- American tech worker, London, UK
Relevant plans
Choose the package that best fits your situation, or view all plans.
- ✓ Everything in Premier
- ✓ Foreign Earned Income Exclusion (Form 2555)
- ✓ Foreign Tax Credit (Form 1116)
- ✓ FBAR filing (FinCEN 114) included
- ✓ Everything in Expat
- ✓ Schedules D & E for investments and rentals
- ✓ Foreign asset reporting (Form 8938)
- ✓ FBAR filing (FinCEN 114) included
- ✓ Self Assessment tax return
- ✓ Employment and basic self-employment income
- ✓ Basic reliefs and allowances
Frequently asked questions about US-UK Dual Tax Filing for Americans Living in the UK
Do I pay tax in both the US and the UK?
You have filing obligations in both countries. However, the US-UK tax treaty and the Foreign Tax Credit work together so that you generally don't pay the same tax twice. UK income tax paid offsets US tax liability on the same income. The actual tax owed to the US is typically zero or small for most Americans in the UK.
Is my UK ISA taxable in the US?
Yes. UK ISAs are not recognised as tax-advantaged by the IRS. Interest, dividends, and capital gains inside your ISA are fully taxable in the US each year. Additionally, any non-UK ETFs or foreign mutual funds held inside your ISA are likely PFICs, triggering Form 8621 obligations.
Can I contribute to my UK employer pension and deduct it in the US?
Not directly as a deduction. Under the US-UK treaty, UK employer pension contributions are generally not treated as current taxable income in the US — they grow as a treaty-based deferral. However, you cannot additionally deduct them. This position requires Form 8833 disclosure on your US return.
I'm a US-UK dual national — which country's rules take priority?
Both countries assert tax residency rights based on their own rules. As a US citizen, you always have a US filing obligation. As a UK resident, you generally have a UK filing obligation. The treaty and Foreign Tax Credit determine who gets the actual tax revenue — usually the UK on UK-source income, with the US making up any small difference.