Dual US-UK citizens
Dual citizens file on both sides — every year, regardless of where you live. The good news: the US-UK treaty and foreign tax credits usually eliminate double tax. The work is in doing it right.
Two passports. Two filing obligations. One opportunity to do it right.
Dual US-UK citizenship is the textbook case for double-taxation relief — the treaty was designed for you. The catch is that the relief is opt-in, not automatic. Foreign tax credits have to be calculated and elected. Treaty positions have to be disclosed on Form 8833. Pension contributions have to be reconciled across both systems. And the timing of major life events — buying property, taking pension distributions, gifting to children — interacts with both tax codes in ways that a single-country preparer routinely misses.
- FTC vs. FEIE election made for total lifetime tax, not just this year
- Treaty positions disclosed on Form 8833 where they meaningfully save tax
- Both-side pension treatment so neither country double-taxes growth
- Renunciation kept on the table as a long-term option without commitment
- 10 yrsFTC carry-forward window
- 0%treaty rate on most US-UK pension distributions
- $2mcovered-expatriate threshold (if you ever renounce)
- 5 yrsFEIE revocation lockout if you switch
What we look at first.
- Filing US returns while UK-resident (or vice versa)
- PFIC rules on UK investments
- Pension treatment under the US-UK treaty
- Renunciation planning if US tax becomes unsustainable
The forms we’ll likely prepare.
- Form 1040 + Form 2555 or 1116
- FBAR and Form 8938
- Form 8833 for treaty elections
- Form 8854 only if you later expatriate
Four steps from intake to filed return.
- 01
Lifetime read
Map the next 10-15 years of your tax life across both countries — major events, residency changes, asset disposals — to make the year-by-year decisions add up.
- 02
Election strategy
Recommend FEIE vs. FTC, residency-based vs. citizenship-based positions, and document the rationale for future preparers.
- 03
Annual coordination
Both returns prepared in lockstep — UK self-assessment and US 1040 with shared positions, shared exchange rates, shared timing.
- 04
Optionality preserved
Track every position so renunciation, return to either country, or cross-border inheritance remains a clean call when you're ready to make it.
Holding both passports felt like a luxury until I tried to file. TaxStone treats it as one tax life across two systems, not two separate problems — and that's exactly what it is.
Common mistakes we see — and fix.
These are the four positions that most often get filed wrong before clients come to us. Sometimes it’s a prior preparer’s call we’d disagree with; sometimes it’s a default election that compounded for years. Either way, we work backwards through them before drafting your return.
- Defaulting to FEIE for life because year one preparer suggested it
- Taking US-source pension distributions without coordinating with UK tax
- Renouncing without 5-year compliance lookback — triggers covered-expatriate status
- Making large gifts without considering both countries' rules
Three snapshots from our practice.
Anonymised, paraphrased, but representative — three of the shapes the work tends to take for dual us-uk citizens.
Lifetime planningLondon-based dual citizen with mid-eight-figure net worth. Annual joint UK/US returns, treaty positioning, and an exit-tax model run every three years to keep renunciation an option.
Inheritance eventUK-side parent passed; dual citizen son inherits property + brokerage. Form 3520 for foreign-trust distribution, basis step-up for US, IHT360 alignment with UK probate accountant.
Business saleSold a UK consultancy to a US group. Capital gains modelled both sides, FTC carry-forward to absorb the US tax, treaty-rate withholding on the earn-out installments.
See if dual us-uk citizens describes your situation.
We'll confirm what you need to file — and just as importantly, what you don't.