401(k)s and workplace pension schemes in the USA. They have comparable schemes in 403b + 457b (generally academic pensions) . 401ks, like in the UK, are pre-tax grossing pensions, so when you take withdrawals, they are treated as ordinary income.
A 401(k) plan is an employer-sponsored, defined-contribution personal pension (savings) account. In the UK, most people are on “defined contribution” pensions, which are similar to the 401 (k) in the USA. A Roth IRA is an individual retirement account (IRA) in which you pay taxes on money going into the account, and then all future withdrawals of earnings are free from tax and penalty.
What to do with a 401 (k) work pension when living in the UK or US as an expat?
With your 401k there are are various options from full withdrawal, regular drawdown, rollover, conversions or leave it alone. Understanding the intricacies can feel like you need to be Einstein. Matching that with processes (checks or cheques as Brits call them, through to posted forms, etc) that often feel like the 1990s, it can be difficult to know what to do. Unlike UK pensions that will tax you at source on pension using your tax code, US workplace pensions are (very) different.
Important Update on US Pension Taxation (March 2025)
HMRC has updated its international manual (INTM163160), reversing a 22-year precedent. Lump-sum distributions from US pension plans (such as a 401k or IRA) to UK residents are now subject to UK income tax. While Foreign Tax Credits (FTC) can be applied for US taxes paid, this significantly changes the tax landscape for US expats. Read our full analysis on HMRC’s landmark shift here.
Understanding 401(k) Plans: Key Insights for US and UK Expats
A 401(k) is America’s most commonly used defined contribution retirement plan. A defined contribution plan allows employees to save for their retirement through tax-deferred contributions. That means that an employee can transfer a fixed portion of their salary (before taxes) into the 401(k) plan while the employer is also contributing, so it’s usually a win-win situation. The real key to this type of retirement plan lies in its flexibility and in the control it provides to individual employees, who can make personal decisions to suit their retirement goals.
What defines a 401(k) as a Defined Contribution Plan?
In a defined contribution, like the 401(k), workers contribute to a retirement account, often supported with additional contributions from the employer. Payments to retirees under a defined contribution plan are not guaranteed: Your eventual benefit is contingent on investment performance, with accumulation of the plan based on contributions, investment product selected, and market conditions. So ensuring you are invested in the right areas that link to your financial situation and circumstances are critical as they influence the pot you have for retirement.
401(k) vs. UK Defined Contribution Plans
In the UK, we have the equivalent of the defined contribution plan, where employees and employers put money into a retirement fund. There are some nuances in the US and the UK. In the US, 401(k) plans are the mainstay of employer-sponsored retirement savings, enabling employees to choose from an extensive menu of investments. In the UK, while defined contribution plans such as SIPPs (Self-Invested Personal Pensions) and QROPS (Qualifying Recognised Overseas Pension Schemes) also offer flexibility in terms of generating robust returns and a huge choice of investment vehicles, similar to IRAs in the US.
US Pensions Contribution Limits and Flexibility
Workers can put a maximum amount into their 401(k) plans, plus a catch-up style contribution that older people can make. There is also an additional employer contribution, which can help increase the total amount of money that can go into one’s plan . 401(k) plans become the most critical retirement savings accounts from a dollar standpoint.
| Category | 2026 | 2025 | 2024 | 2023 | 2022 | 2021 |
|---|---|---|---|---|---|---|
| DB 415(b)(1)(A) | 290000 | 280,000 | 275,000 | 265000 | 245000 | 230000 |
| DC 415(c)(1)(A) | 72,000 | 70,000 | 69,000 | 66000 | 61000 | 58000 |
| Maximum Deferral 401(k) & 402(g)(1) | 24,500 | 23,500 | 23,000 | 22500 | 20500 | 19500 |
| Over 50 Catch-up Contribution | 8000 | 7500 | 7500 | 7500 | 6500 | 6500 |
| 403(b) | 24,500 | 23,500 | 23,000 | 22500 | 20500 | 19500 |
| SIMPLE | 17,000 | 16,500 | 16000 | 15500 | 14000 | 13500 |
| SIMPLE Over 50 Catch-up Contribution | 4,000 | 3,500 | 3500 | 3500 | 3000 | 3000 |
| 457 1(B) | 24,500 | 23,500 | 23000 | 22500 | 20500 | 19500 |
| Highly Compensated Definition Limits Under IRC 414(q) | 160,000 | 160,000 | 155000 | 150000 | 135000 | 130000 |
| Annual Comp Limit 401(a)(17), 404(l), 408(k)(3)(C) | 360,000 | 350,000 | 345000 | 330000 | 305000 | 290000 |
| Taxable Wage Base | 184,500 | 176,100 | 168600 | 160200 | 147000 | 142800 |
| Age 60–63 Super Catch-up (SECURE 2.0) | 11,250 | 11,250 | N/A | N/A | N/A | N/A |
* from 2026, anyone who earned over $150,000 in FICA wages from the plan sponsor in the prior year must make all catch-up contributions (including the enhanced 60–63 amount) on a Roth basis.
UK Pensions Contribution Limits and Flexibility
By contrast, the table for the UK pension contribution limits is below. It includes details such as the annual allowance, lifetime allowance, personal contribution limit, tapered annual allowance, and the Money Purchase Annual Allowance (MPAA).
| Category | 2026 | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 |
|---|---|---|---|---|---|---|---|
| Annual Allowance | £60,000 | £60,000 | £60,000 | £40,000 | £40,000 | £40,000 | £40,000 |
| Lifetime Allowance | LSA/LSDBA | LSA/LSDBA | LSA/LSDBA | £1,073,100 | £1,073,100 | £1,073,100 | £1,073,100 |
| Personal Contribution Limit | 100% of earnings | 100% of earnings | 100% of earnings | 100% of earnings | 100% of earnings | 100% of earnings | 100% of earnings |
| Tapered Annual Allowance | £10,000 – £60,000 | £10,000 – £60,000 | £10,000 – £60,000 | £4,000 – £40,000 | £4,000 – £40,000 | £4,000-£40,000 | £4,000 – £40,000 |
| Money Purchase Annual Allowance (MPAA) | £10,000 | £10,000 | £10,000 | £4,000 | £4,000 | £4,000 | £4,000 |
Rollover Options: Flexibility and Considerations
When changing jobs or leaving employment, 401(k) holders can roll over their funds into an IRA (Individual Retirement Account) or another 401(k) plan, continuing their tax-deferred growth and, in many cases, also broadening their investment options. British expats returning to the UK have some unique challenges. Rules prohibit a direct transfer of their 401(k) funds into a UK pension scheme. Nevertheless, it is still possible for them to manage their funds effectively, using a combination of IRAs and SIPPs, in ways that maximise tax benefits and broaden investment opportunities.
Should I transfer my 401(k)?
This is the question we are asked more than any other by clients who have returned to the UK with a 401(k) left behind in the US. The honest answer is that “transfer” means different things to different people, and the right route depends on your age, the size of the plan, your residency and citizenship status, and what you want the money to do. Below we set out the main options and — importantly — explain why a direct transfer into a UK pension is almost never one of them.
Option 1: Roll your 401(k) into an IRA
For many people who have left a US employer, rolling the 401(k) into an Individual Retirement Account (IRA) is the most practical step. A direct, trustee-to-trustee rollover from a 401(k) to a Traditional IRA is not a taxable event in the US, and it keeps the funds inside a US tax-advantaged wrapper that the UK/US double taxation treaty recognises.
The advantages of an IRA rollover for a UK resident typically include:
- Consolidation. If you worked for several US employers, you may hold multiple 401(k) and 403(b) accounts. Bringing them into a single IRA simplifies administration, required minimum distribution (RMD) planning and reporting.
- Wider investment choice. 401(k) menus are often limited to a short list of funds chosen by the employer. An IRA opens up the full universe of US-listed funds and ETFs — without the PFIC problems that affect non-US funds held outside a pension wrapper.
- Control over withholding and treaty claims. With your own IRA and the correct forms in place, it is easier to manage US withholding on withdrawals and claim the correct treatment under the UK/US treaty.
- Roth conversion planning. Once funds are in a Traditional IRA, staged conversions to a Roth IRA become possible — a strategy that can be particularly attractive for UK residents because of how the treaty treats conversions and Roth income. This is a specialist area and the sequencing matters, so take advice before converting.
The main practical hurdle is finding a custodian. Many mainstream US brokerages pr custodians are now restricting or closing accounts once you register a UK residential address. Working with an adviser experienced in cross-border arrangements means the rollover can be placed with a custodian that accepts UK-resident clients from the outset, rather than discovering the problem after the transfer paperwork has started.
Option 2: Leave the 401(k) with your former employer
Doing nothing is a legitimate option, and in some cases the right one. Reasons to stay put include:
- Institutional pricing. Large employer plans often have access to very low-cost institutional share classes and stable value funds that are not available in retail IRAs.
- ERISA protections. 401(k) plans generally enjoy strong federal creditor protection.
- The Rule of 55. If you left that employer in or after the year you turned 55, you may be able to take penalty-free withdrawals from that plan before age 59½ — a facility you lose if you roll the money into an IRA.
But there are real risks for someone living in the UK:
- Small balances can be forced out. Plans can automatically cash out balances under $1,000 and force balances between $1,000 and $7,000 into a default IRA. A cheque posted to an out-of-date US address is a common and expensive mess to untangle.
- Communication breaks down. Plan administrators are set up for US-resident participants. Statements go astray, online access gets locked to US phone numbers, and some plans restrict transactions for participants with foreign addresses.
- Limited investment menu and no personal advice. You are restricted to the plan’s fund list, and the plan will not help you think about UK tax, currency or drawdown strategy.
If you leave a plan in place, at minimum make sure your address and beneficiary nominations are current, your online access works from the UK, and you understand what the plan will do with your balance if it is below the forced-rollover thresholds.
Option 3: Transferring to a UK pension — what people expect, and the reality
Clients returning to the UK often assume they can move a 401(k) into a SIPP or workplace pension in the same way they might consolidate two UK pensions. It feels intuitive: both are retirement accounts, and a well-publicised transfer regime (QROPS/ROPS) exists for pensions crossing borders. Unfortunately, that regime runs in the other direction — it exists to move UK pensions overseas, not to bring US plans into the UK.
Why most 401(k)s cannot simply be transferred into a UK pension
The obstacle is not one rule but a combination of US and UK rules that, together, close the door for almost everyone:
- The IRS only permits rollovers into eligible US plans. US law allows tax-free rollovers from a 401(k) only into another qualified US plan or an IRA. A UK pension scheme is not an eligible recipient. Moving money to a UK scheme therefore means taking a distribution first.
- A distribution is a taxable event. The withdrawal is subject to US tax, and if you are under 59½ an additional 10% early withdrawal penalty usually applies. Following HMRC’s 2025 change of interpretation on lump sums, a UK-resident recipient may also face UK tax on the same payment, with relief for the US tax paid — but the combined effect can still be a substantial haircut before a penny reaches a UK scheme.
- The UK side gives you nothing back. Money arriving from a cashed-out 401(k) is simply cash. Paying it into a SIPP counts as a brand-new contribution, limited by your annual allowance (currently £60,000) and, for tax relief purposes, by your relevant UK earnings. There is no mechanism to “transfer in” the full value of a large US plan in one move.
- No treaty shortcut exists. The UK/US double taxation treaty protects pensions where they sit and governs how withdrawals are taxed, but it contains no provision allowing a tax-neutral transfer of funds from a US retirement plan into a UK registered pension scheme.
The practical conclusion for the vast majority of people is this: your 401(k) should stay inside a US wrapper — either the existing plan or an IRA — and be managed as part of a coordinated UK/US strategy, rather than being cashed out and rebuilt in the UK. Held correctly, a US retirement account remains a highly tax-efficient asset for a UK resident: it grows free of UK tax while invested, and withdrawals can be planned around both countries’ rules and the treaty.
Edale has advised on US/UK cross-border investing since 2000. We can review your 401(k) alongside your UK pensions, model the tax treatment of different withdrawal and rollover strategies under the current HMRC guidance, and arrange IRA custody that works for UK residents. Book an introductory call to discuss your situation.
Managing 401(k) Plans as a British Expat
A British citizen working in the US and funding a 401(k) might incur some costs, time and onerous tax considerations when deciding what to do with her retirement money upon a return to the UK. Various questions to consider include:
- Rollover rights: Before moving back to the UK, expats can roll over their 401(k) into an IRA to take advantage of the tax-deferred status (and avoid penalties that would be incurred with an early withdrawal) and get more flexibility to take out money in the event of an emergency medical issue, for college tuition, or to purchase your first home.
- Cashing Out: If you receive a distribution before you are 59½ years old, you’ll be hit hard with a 10 per cent penalty, plus income tax on every penny you get your hands on. If possible, another option is to wait to remove money from the pot until after you’ve moved overseas and are no longer earning US income.
- Get professional help: thanks to the complicated interactions of the US and UK tax regimes, maximising the usage of your retirement funds while minimising tax payments requires expert advice. Consulting a financial broker with experience in cross-border taxation can help.
International Considerations: Moving Your 401(k) Abroad
You cannot transfer a US pension to another jurisdiction. Current law precludes direct IRS-approved transfers of 401(k) plans to foreign pension plans because foreign pension arrangements do not satisfy the US Internal Revenue Code qualification requirements for tax-qualified retirement plans. A 401(k) cannot be rolled or transferred into any type of non-US plan, including UK pensions, Australian superannuation or Canadian RRSPs.
One possibility is to roll your 401(k) into a US-based IRA (Individual Retirement Account). IRAs have more flexibility and wider investment choices. Once rolled over to an IRA, the money is yours – you can manage it or take withdrawals according to the rules of the country in which you now live. If you withdraw funds from the IRA, you can transfer them to an account abroad, but you’ll still have to pay tax on them under US rules and, in many cases, under local rules too.
U.S. Taxes: Money withdrawn from the 401(k) is taxable in the U.S. and will incur an extra 10 per cent penalty if you take it out early (before age 59½). Foreign Taxes: the amount distributed overseas may be subject to taxation in the receiving country; a U.S. tax treaty with the country of residence may prevent double taxation.
- Historically, under Article 17(2) of the US-UK Double Taxation Agreement, lump-sum withdrawals from a 401(k) were strictly taxable in the US and exempt from UK tax. As of March 2025, this is no longer the case. HMRC now invokes the treaty’s “saving clause,” meaning lump-sum withdrawals are subject to UK income tax (up to 45% or 48% in Scotland). If you are a UK resident taking a lump-sum distribution, you will owe UK tax on the withdrawal, though you can claim a Foreign Tax Credit (FTC) for any US taxes already paid to mitigate double taxation.
Cross-border pension advice is complex and burdensome with tax. If you want to transfer your pension to another country or request withdrawal for your U.S. pension, you may need to consult with a financial planner or tax professional who is familiar with international and U.S. tax laws to formulate a strategy to minimise your tax burden or to make your financial goal achievable.
What to do with your 401k after leaving the USA?
An expat with pension assets in the US and UK needs a suitable adviser who is qualified in both the UK and the US. Distributions from a 401(k) plan can’t be rolled over into a UK pension. Getting an adviser to help with US and UK pensions is possible. Some overseas groups do it from offices abroad and use local financial licenses from parent companies. Ideally you want to optimise the retirement savings with an adviser that is resident in the UK or US. With pensions in multiple jurisdictions try to balance financial decisions with support from an adviser. Once again, consulting a financial adviser well-versed in the intricacies of each pension scheme to develop a plan tailored to your needs is encouraged.
Our expat work means for US / UK residents we are frequently a recommended IFA for US citizens in the UK
Lawrie Chandler, Financial and Wealth Expert for Americans in the UK