US–UK wealth planning is the work of organising a family’s money so that it makes sense under both the American and the British tax systems at once, in two currencies, over a whole lifetime. It matters because the two systems tax different things, at different times, and on different definitions, so a plan that is sensible in one country can be expensive in the other. This guide explains where the two systems meet, what goes wrong most often, and how an integrated approach to tax, investments, planning and reporting deals with it.
What is US–UK wealth planning?
It is financial planning for households whose income, savings, pensions, property, family or future sit on both sides of the Atlantic. The goals are the ordinary ones: enough to live on, security for a partner, something left for children. What makes it different is that every decision has two tax answers, two sets of reporting rules and a currency attached.
A single-country plan asks “what does this cost in tax?” A cross-border plan has to ask the same question twice and then ask how the two answers interact. For a US citizen living in London, UK income tax is usually paid first and then credited against the US bill[11]. That credit often removes the US tax on a salary altogether. It does much less for income the UK does not tax but the US does (ISA income, for example), for the 3.8% net investment income tax, and for gains that exist in dollars but not in pounds.
Who needs US–UK wealth planning?
Anyone for whom one country’s rules cannot describe their whole position. In practice, the families we see fall into a handful of groups.
| Situation | First issues to look at | Guide |
|---|---|---|
| US citizen or green card holder living in the UK | Filing in both countries, foreign tax credits, ISAs and UK funds (PFIC), UK pension lump sums, FBAR and Form 8938 | Americans in the UK |
| Briton back in the UK with a 401(k) or IRA | UK tax on distributions, Roth treatment, required minimum distributions, currency | US retirement accounts |
| UK resident inheriting a US IRA | The ten-year rule, annual minimums, UK income tax, timing | Inherited IRAs |
| Family planning a move either way | Residence tests, split years, the UK’s four-year FIG regime, what to do before leaving | Moving |
| Couple with a US-citizen and a non-US spouse | US estate and gift limits between spouses, UK inheritance tax, the estate tax treaty | Estates |
| Retirees with dollar assets and sterling spending | Currency risk, sustainable spending, drawdown order, pensions from both countries | Currency |
“Accidental Americans” (people who hold US citizenship by birth but have lived almost entirely in the UK) belong in the first group. The US rules apply to them in full, whether or not they have ever filed.
Why can’t you plan each country separately?
Because the two systems overlap rather than divide the world between them. The treaty decides which country taxes first and which gives credit, but its saving clause preserves the US right to tax its own citizens, so for a US person the treaty mostly prevents double tax rather than removing a layer of tax[3]. Four mismatches matter most.
- Different definitions of tax-free. An ISA is tax-free in the UK and fully taxable in the US. A Roth IRA is tax-free in the US and, on HMRC’s published view, its qualified distributions are generally exempt in the UK too, but only because of specific treaty wording[12]. The UK 25% tax-free pension lump sum is generally regarded as taxable in the US for a US citizen[12], and HMRC now says the UK can tax lump sums from US pensions paid to UK residents, with credit for US tax[13].
- Different timing. The two tax years do not line up (6 April and 1 January), so income and credits can fall into different years. Inherited IRAs have US deadlines that take no account of what else is in the UK tax year.
- Different currencies of measurement. HMRC measures a gain in pounds; the IRS measures it in dollars. The same sale can be a gain in one and a loss in the other.
- Different ideas of who is taxable on death. The UK looks at long-term residence; the US at citizenship and domicile. A 1978 estate tax treaty settles some conflicts but not all[14].
Each country’s adviser can get their own half right and the household can still overpay, because the expensive decisions are the ones that trade one country’s tax against the other’s over many years.
What are the five parts of a cross-border plan?
A complete plan covers tax, investments, retirement income, the estate, and reporting. They are listed separately here, but the value comes from treating them together.
| Part | The central question | Typical cross-border issues |
|---|---|---|
| 1. Tax optimisation | Across both systems and every year, what does the household keep? | Foreign tax credits, treaty elections, the UK personal allowance taper, US brackets, Roth conversions, timing of withdrawals |
| 2. Investments across two markets | Which assets, in which accounts, in whose name and currency? | PFIC and UK reporting-fund status, dividend withholding, asset location across ISA, SIPP, IRA and Roth, currency of assets vs spending |
| 3. Retirement income | How much can be spent, from where, in what order? | State Pension and Social Security, inherited accounts, drawdown order, sequence and currency risk |
| 4. Estate and protection | What reaches the next generation, and what happens if one partner dies first? | UK inheritance tax, US estate and gift tax, non-citizen spouses, pensions from April 2027, cover gaps |
| 5. Reporting and records | What must be filed, and can the figures be trusted? | UK Self Assessment, US 1040 with Forms 1116, 8938, 8621 and FBAR, exchange rates, share-matching rules |
1. Tax optimisation across both systems
The largest savings usually come from timing: when income is taken, from which account, and in which country’s tax year. Pension contributions are a good example of how uneven UK relief is. In the example below, a £10,000 gross contribution earns £2,000 of relief at a £30,000 salary but £6,000 at £110,000, because it restores personal allowance lost to the taper. For a US citizen, the US side may give a deduction for contributions to a UK employer’s scheme under treaty Article 18(5), up to US plan limits[3]. See UK pensions for Americans.
2. Investments across two markets
The same fund can be efficient for one family member and damaging for another. A UK-domiciled fund is ordinary for a UK taxpayer and a PFIC for a US person[4]. A US-domiciled ETF suits the US person but, without HMRC reporting-fund status, its gains are taxed as income in the UK. Dividends from US shares carry 15% US withholding for a UK resident with a treaty claim, and can be 0% inside a pension[3]. See Investing across US and UK markets and ISAs, UK funds and PFIC rules.
3. Retirement income and pensions
Cross-border retirees often have four or five sources of income with different tax treatment and different start ages. Under treaty Article 17(3), social security is taxed only in the country where the recipient lives, and this overrides the saving clause, so a US citizen living in the UK pays tax on Social Security only in the UK[3][15]. See Social Security and the UK State Pension and How much can I spend?
4. Estate and protection
UK inheritance tax is 40% above the available nil-rate bands; the residence nil-rate band tapers away above £2 million[16]. From 6 April 2027 unused pension funds count towards the estate, which can push a family over that threshold[6]. On the US side, the large exclusion protects most estates of US citizens, but a non-US-citizen spouse does not get the unlimited marital deduction without a qualified domestic trust[7]. See UK inheritance tax and US estate tax.
5. Reporting and records
US persons abroad face information returns with penalties that bear no relation to tax owed: the FBAR above $10,000 in aggregate, Form 8938 above $200,000 at year-end for a single filer living abroad, and Form 8621 for each PFIC[9][10][4]. UK gains are matched to purchases under same-day, 30-day and pooling rules; US gains use first-in, first-out or specific identification[17]. See Tax reporting for investors with US and UK accounts.
Where do cross-border plans most often go wrong?
The same problems recur, and most are cheaper to prevent than to repair.
| Problem | Why it happens |
|---|---|
| A US person buys UK funds or opens a stocks and shares ISA | UK providers treat ISAs as tax-free; the US does not, and UK funds are usually PFICs |
| Tax-free cash taken from a UK pension without checking the US position | The UK exemption is not generally recognised by the US for its citizens |
| An inherited IRA left to the ten-year deadline, or emptied in a hurry | Both can land large payments in high-tax years; the right answer depends on the household’s income path |
| Dollar assets held against sterling spending with no view on currency | A stronger pound cuts the sterling value of dollar savings; sterling rose by close to 40% in both 1985–90 and 2001–07 |
| A long-term UK resident assumes a US will covers UK inheritance tax | UK IHT now depends on long-term residence, and pensions enter the estate from April 2027 |
| A move planned around the removal date rather than the tax year | Residence tests, split-year cases and pre-arrival steps decide what each country taxes |
| Missing FBAR or Form 8938 filings | UK accounts, pensions and ISAs are all “foreign” to the US |
Worked examples: four questions, answered in Edale’s planner
All four use fictional households and stated assumptions. They are illustrations of how the planner is used, not forecasts, and the results are not guaranteed. Tax rules are those in force or legislated at the time of writing; individual circumstances change the answer.
The core household is a fictional couple, Alex (50, a US citizen, salary about £94,000) and Sam (48, salary about £38,000), living in the UK and planning to retire at 60, with UK pensions, ISAs, a general investment account and a US brokerage account.
| Question | What the planner found |
|---|---|
| Alex is a US citizen. How much extra tax does that cost this year? | UK income tax £28,988 and National Insurance £5,949 for the household. Alex’s US liability before credits, about £15,246 in sterling terms, is entirely covered by foreign tax credits, so the US top-up is £0. Total tax is the same as for a non-US household (£34,937). The filing obligations remain. |
| What is a £10,000 gross pension contribution worth at different salaries? | Total relief of £2,000 at £30,000; £2,946 at £55,000; £4,000 at £80,000; £6,000 at £110,000; £4,500 at £150,000. |
| Alex inherits a $600,000 IRA under the ten-year rule. How should it be drawn? | If they keep working to 60, taking the minimum and a large final payment scored best, and the optimiser agreed. If they retire at 52 and spend 20% less, the optimiser’s schedule leaves about £1.35m of after-tax wealth in today’s money, against £1.18m for minimum-only and £0.92m for emptying it in three years. |
| They hold $700,000 in US accounts and spend in pounds. What if sterling strengthens? | Usable money at 85 (today’s money) is £2.82m with the exchange rate unchanged, £2.33m if the 2001–07 rise in sterling repeats from retirement, and £4.08m if the 1980–85 collapse repeats. |
Show the figures
| Currency path from retirement | Usable money at 85 |
|---|---|
| Exchange rate unchanged | £2,820,293 |
| Sterling's climb to $2.00 (2001–07) | £2,333,802 |
| Sterling's recovery (1985–90) | £2,349,026 |
| Brexit referendum era (2014–19) | £3,278,220 |
| Sterling collapse (1980–85) | £4,078,621 |
None of these answers can be reached by looking at one country at a time. The first depends on how UK tax credits against US tax; the third on how an American deadline interacts with UK income tax bands; the fourth on dollar assets measured against sterling spending. The detailed articles explain each one: dual taxation, pension relief, inherited IRAs and currency.
Why do tax, investments, planning and reporting belong together?
Because each depends on the others, and the handovers between separate advisers and tools are where cross-border mistakes happen.
- The plan needs real holdings. A projection built on a guessed portfolio will miss the PFIC in an ISA, the currency of a brokerage account and the tax already withheld on dividends.
- Investment choices need the plan. Whether a US-domiciled ETF or a UK fund is right depends on whose account it sits in, which wrapper it is in, and when the money will be spent.
- Tax optimisation needs a lifetime view. A Roth conversion, a pension contribution or an inherited IRA payment is a trade between this year’s tax and later years’ tax in two countries. It can only be judged across the remaining lifetime.
- Reporting closes the loop. Accurate records of gains, income and withdrawals in both currencies make each year’s returns cheaper to prepare and show whether the plan is being followed.
An integrated platform does not remove the need for specialist tax preparers in each country. It gives the household and its advisers one consistent set of figures to work from.
How the Edale Wealth Hub helps
The Edale Wealth Hub is the secure client platform we use with the families we advise. It brings the four parts of the work into one place.
- Planning across both tax systems. Edale’s cashflow planner models a household year by year across the US and UK, in any mix of currencies. It holds the account types that matter on both sides: 401(k)s, IRAs, Roth and inherited IRAs, Social Security, SIPPs, workplace and defined benefit pensions, the State Pension, ISAs and investment bonds. It applies UK income tax (including Scottish rates), National Insurance, CGT and inheritance tax, alongside US federal income tax, payroll taxes and the net investment income tax, and works out how the two interact for US persons. US estate tax and US state taxes are not modelled.
- Specialist tools. Advisers can model Roth conversions year by year, plan 72(t) early access across the three IRS methods, compare an annuity with drawdown, and use an Inherited IRA optimiser that searches for the distribution schedule leaving the most after-tax wealth, never below the legal minimum.
- Testing the plan. Monte Carlo simulation, replayed market history, sequence-of-returns tests, twelve named currency episodes back to 1980, longevity against ONS tables, and a solver for the most a household can spend and still meet its plan.
- Investments in one view. For Interactive Brokers accounts in the UK and US that we link, My Investments shows holdings, transactions, income and performance in pounds or dollars, with ISA allowance tracking.
- Tax reporting support. Capital gains, dividends and interest year to date in both currencies, and a 1099-style US tax summary with Form 8949 detail and PFIC flags, for sharing with your accountant or tax preparer. These are summaries, not tax returns or IRS forms.
- Advice and records. Written reports are released through a secure portal once an adviser approves them, alongside a risk profile, documents, messages and records of Roth conversions and US pension withdrawals.
Software does not give advice. The planner informs recommendations made by a qualified adviser who understands your circumstances. You can read more about the planner or arrange a conversation.
The guides in this series
- Americans living in the UK: how both tax systems apply
- ISAs, UK funds and PFIC rules for Americans
- UK pensions for Americans
- 401(k)s, IRAs and Roth IRAs when you live in the UK
- Inheriting a US IRA while living in the UK
- GBP/USD currency risk in retirement
- UK inheritance tax and US estate tax
- Moving between the UK and the US
- Social Security and the UK State Pension
- How much can I spend in retirement?
- Investing across US and UK markets
- Tax reporting for investors with US and UK accounts
Frequently asked questions
Do Americans living in the UK pay tax twice?
Usually not on the same income, but they file twice. The US taxes citizens wherever they live, and the UK taxes its residents. The treaty and US foreign tax credits normally stop the same salary being taxed in full by both, because UK tax is credited against the US bill. Gaps remain, for example ISA income, the net investment income tax and some pension lump sums.
Can a US citizen have an ISA?
Yes, a UK resident US citizen can open one, but the US does not recognise ISAs, so the income and gains are taxable on the US return. Funds held inside an ISA are often PFICs, which carry punitive default US tax and annual Form 8621 filing. Cash ISAs avoid the PFIC problem but their interest is still taxable in the US.
Is my UK pension taxed in the US?
Growth inside a UK pension is generally not taxed in the US until it is paid out, under Article 18(1) of the treaty, and this applies to US citizens. Payments are taxable, and the 25% tax-free lump sum is generally regarded as taxable in the US for US citizens. Contributions to a UK employer’s scheme may be deductible within US limits.
Who taxes my Social Security if I live in the UK?
Under Article 17(3) of the US–UK treaty, social security is taxed only in the country where the recipient lives, and this overrides the saving clause. A UK resident, including a US citizen, pays tax on US Social Security only in the UK. A US resident pays tax on the UK State Pension only in the US.
Does UK inheritance tax apply to Americans living in Britain?
UK assets are always within the scope of UK inheritance tax. Since 6 April 2025 worldwide assets are within scope once someone has been UK resident for at least 10 of the previous 20 tax years. The 1978 US–UK estate tax treaty can change the result for some people and gives credit for tax paid to the other country.
What is the most expensive cross-border mistake?
It varies, but the costliest are usually slow and silent: holding UK funds or ISAs as a US person for many years, taking large retirement or inherited-account payments in high-tax years, and holding the wrong currency against future spending. Missed FBAR and Form 8938 filings can also bring penalties unrelated to any tax owed.
Why use one platform for planning, investments and tax reporting?
Because cross-border decisions depend on all three. A plan needs the real holdings and their tax status; investment choices depend on whose account and which country’s tax applies; and accurate records in both currencies make returns easier to prepare. One consistent set of figures reduces the gaps between separate advisers and tools.
Is this guide personal advice?
No. It is general information about rules that change and apply differently to each person. Whether any approach suits you depends on your circumstances, and you should take advice from a qualified adviser, and a tax preparer in each country where you file, before acting.
Sources
- IRS — Publication 54, Tax guide for US citizens and resident aliens abroad (accessed September 2026)
- HMRC — RDR3: Statutory Residence Test guidance note (accessed September 2026)
- US Treasury — US–UK income tax convention (2001) (accessed September 2026)
- IRS — Instructions for Form 8621 (accessed September 2026)
- legislation.gov.uk — Inheritance Tax Act 1984, section 6A (long-term UK resident) (accessed September 2026)
- GOV.UK — Technical note: Inheritance Tax on pensions (accessed September 2026)
- IRS — Revenue Procedure 2025-32 (2026 inflation adjustments) (accessed September 2026)
- Federal Register — Required Minimum Distributions, final regulations (TD 10001), 19 July 2024 (accessed September 2026)
- IRS — Report of Foreign Bank and Financial Accounts (FBAR) (accessed September 2026)
- IRS — Comparison of Form 8938 and FBAR requirements (accessed September 2026)
- IRS — Publication 514, Foreign tax credit for individuals (accessed September 2026)
- HMRC — Double Taxation Relief Manual DT19853, US/UK treaty: pensions (accessed September 2026)
- HMRC — International Manual INTM163160, Pensions: lump sums (accessed September 2026)
- Joint Committee on Taxation — Explanation of the US–UK estate and gift tax treaty (accessed September 2026)
- IRS — Publication 915, Social Security and equivalent railroad retirement benefits (accessed September 2026)
- GOV.UK — Inheritance Tax (accessed September 2026)
- HMRC — HS284 Shares and Capital Gains Tax (accessed September 2026)