Introduction Pension and retirement wealth planning for a US citizen living in the UK involves four separate retirement vehicles — the UK SIPP, the US 401(k), the traditional IRA, and the Roth IRA — each with its own US and UK tax treatment, treaty interaction, and annual reporting obligation. A US-UK cross-border tax specialist who […]
Pension and retirement wealth planning for a US citizen living in the UK involves four separate retirement vehicles — the UK SIPP, the US 401(k), the traditional IRA, and the Roth IRA — each with its own US and UK tax treatment, treaty interaction, and annual reporting obligation.
A US-UK cross-border tax specialist who understands all four simultaneously is the only adviser who can build a retirement plan that works efficiently under both systems. The wrong decisions — failing to make the Article 17 SIPP election, missing the annual RMD, omitting the SIPP from the FBAR, or making the mark-to-market PFIC election inside the SIPP — each carry significant consequences. This guide covers every dimension of pension and retirement wealth planning for US citizens in the UK in 2026. Visit our advisory service:
https://www.jungletax.co.uk/services/us-uk-tax/
US UK cross-border tax specialist for pension and retirement planning means an adviser who understands the UK SIPP — including the Article 17 treaty election, the annual FBAR reporting requirement, and the PFIC treatment of non-US funds inside the SIPP — and the US 401(k), traditional IRA, and Roth IRA — including the UK tax treatment of distributions, the RMD rules, and the rollover options before UK arrival. They model every retirement vehicle under both systems simultaneously.
The IRS guidance on retirement plans for US citizens abroad is at:
https://www.irs.gov/retirement-plans/retirement-plans-for-expatriates
Each retirement vehicle is taxed differently in the UK and the US — and the interactions are not symmetric. A SIPP that grows tax-free in the UK generates UK tax on withdrawal — but the Article 17 election defers US tax on the same growth. A Roth IRA that grows tax-free in the US may generate UK income tax on the growth inside the wrapper — because the UK does not automatically recognize the Roth’s tax-exempt status. Only a US-UK cross-border tax specialist models these interactions correctly for each vehicle.
The Article 17 election that defers US tax on SIPP growth is not automatic — it must be made on Form 8833 on every annual US federal return. Missing it in any year triggers immediate US tax on the SIPP growth for that year — destroying the UK tax deferral. Many non-specialist advisers prepare the US return without electing under Article 17 because they do not know it exists. The US-UK cross-border tax specialist includes it as a mandatory item on every return.
Required minimum distributions from traditional IRAs begin at age 73. RMDs must be taken annually — regardless of whether the IRA holder is living in the UK. Failure to take the RMD triggers a 25 percent excise tax on the amount missed (reduced to 10 percent if corrected within 2 years). A US citizen in the UK who does not receive reminders from their US IRA custodian may miss the deadline without realizing it.
Our guide to PFIC rules and UK investment wrappers — including SIPP treatment — is at:
A Roth IRA is tax-free in the United States — qualified withdrawals are entirely exempt from US federal income tax. The UK does not automatically recognize this exemption. A UK resident who holds a Roth IRA may be subject to UK income tax on income or growth inside the wrapper. The US-UK cross-border tax specialist confirms the UK tax treatment of the Roth IRA before advising on contributions or conversions.
A UK Self-Invested Personal Pension is a UK-registered pension scheme. SIPP contributions receive UK income tax relief, growth is tax-deferred, and withdrawals are subject to UK income tax. From a US perspective, the SIPP is a foreign pension fund — not a US-qualified retirement plan. Without the Article 17 treaty election, SIPP growth is taxable in the United States in the year it arises.
The Article 17 election — made on Form 8833 as part of the annual US federal return — defers US tax on SIPP growth until withdrawal. SIPP contributions do not receive US tax relief. SIPP withdrawals are subject to both UK income tax and US federal income tax, with the FTC from UK income tax typically offsetting most of the US liability. The SIPP is also a foreign financial account for FBAR purposes — its peak market value must be reported annually.
A 401(k) held with a former US employer generates no current income while in accumulation — so it does not appear on the UK self-assessment during that period. Distributions from the 401(k) are subject to both US federal income tax and UK income tax in the year of distribution, with the FTC from US federal income tax typically offsetting the UK liability. Rolling the 401(k) to a self-directed IRA before UK arrival — completed before the UK arrival date to avoid UK CGT interaction — provides full investment flexibility and simplified administration from the UK.
A traditional IRA in accumulation generates no current UK income — the growth inside the wrapper is deferred. IRA distributions are subject to US federal income tax as ordinary income. For a UK resident, the same distributions are also subject to UK income tax, with the FTC from US income tax typically offsetting the UK liability. The RMD must be taken by 31 December each year from age 73.
The IRS RMD guidance is at:
https://www.irs.gov/retirement-plans/plan-participant-employee/required-minimum-distributions-rmds
A Roth IRA is funded with after-tax contributions — qualified distributions are entirely exempt from US federal income tax. The UK does not automatically recognize this tax-exempt status. The UK may treat the Roth IRA’s annual income and growth as taxable for UK income tax purposes — even though no US tax is due. The US-UK cross-border tax specialist reviews each client’s Roth IRA structure and confirms the UK tax treatment before advising on contributions or conversions.
Edward is a US citizen who moved from Boston to Edinburgh in 2011. He is now aged 68. He holds a UK SIPP with Hargreaves Lansdown (current value £380,000, invested in three UCITS equity funds), a traditional IRA held with Fidelity ($290,000), and a Roth IRA ($85,000). He receives a defined-benefit pension from his UK employer of approximately £18,000 per year starting at age 65. The SIPP Article 17 election had not been made on any of his prior US returns — his Boston CPA was unaware of the election.
Jungle Tax filed amended returns for the open years with the Article 17 election — resolving the retrospective US tax exposure on SIPP growth for those years.
The SIPP UCITS funds were reviewed for PFIC status — all three are PFICs. No mark-to-market election was made because the Article 17 election covers the SIPP growth, and the mark-to-market election would conflict with it. Form 8621 was filed for each fund for every year of SIPP ownership, closing the open statute of limitations.
The UK tax treatment of the Roth IRA was confirmed — HMRC accepted its tax-exempt status under the treaty. The Roth is included on the FBAR and Form 8938 annually.
The RMD plan was established at age 73, with annual reminders set for October each year, starting in 2031. The IRA distribution plan was modeled, confirming that the FTC will largely offset UK income tax on IRA distributions from US federal income tax on the same distributions.
The Article 17 election was applied retrospectively — eliminating the US tax on SIPP growth for prior years. Form 8621 was filed for all three UCITS funds across all open years, closing the indefinite statute of limitations. The RMD program was established. The combined annual compliance program now covers the Article 17 election, FBAR (SIPP, IRA, Roth), Form 8938, Form 8621, and the RMD calendar.
The Article 17 election is not automatic. It must be made on Form 8833 on every annual US federal return. Missing it in any year triggers immediate US tax on the SIPP growth for that year. Many non-specialist advisers are not aware of the election. The US-UK cross-border tax specialist includes it as a mandatory checklist item for every return.
A SIPP is a foreign financial account. Its peak market value must appear on the FBAR for any year the aggregate foreign account threshold is met. Many US citizens in the UK overlook the SIPP because they view it as a pension rather than a financial account. This is a material FBAR omission.
The RMD must be taken from all traditional IRAs and 401(k) accounts by 31 December each year, starting at age 73. The excise tax is 25 percent of the missed distribution amount, reduced to percent if corrected within two years. The adviser monitors the RMD obligation and alerts the client before the December deadline each year.
The mark-to-market election and the Article 17 SIPP election conflict. Marking to market on PFIC positions held in the SIPP triggers current US tax, defeating the Article 17 deferral. Never make the mark-to-market election for PFIC positions inside a SIPP where the Article 17 election is in place.
The IRS guidance on foreign pensions is at:
https://www.irs.gov/individuals/international-taxpayers/foreign-pension-plans
Jungle Tax is a specialist US-UK cross-border tax advisory firm with US-UK cross-border tax specialists who include IRS Enrolled Agents and UK-qualified tax practitioners experienced in planning and reporting retirement wealth across all four vehicles. We make the Article 17 SIPP election on every annual US federal return, include the SIPP on the FBAR and Form 8938 annually, monitor the RMD obligation from age 73, coordinate the PFIC elections with the Article 17 election, and confirm the UK tax treatment of the Roth IRA. We advise on 401(k) rollover timing before arrival in the UK and establish a complete annual retirement compliance program.
Read our guide to pre-departure planning — including 401 (k) rollover timing:
Pension and retirement wealth planning for a US citizen in the UK requires a US UK cross-border tax specialist who understands every retirement vehicle — the SIPP, the 401(k), the traditional IRA, and the Roth IRA — and who manages the treaty elections, FBAR reporting, and RMD obligations across all four simultaneously.
Three points matter most. First, the Article 17 SIPP election must be made on every annual US federal return — it is not automatic, and failing to make it triggers immediate US tax on SIPP growth. Second, the SIPP is a foreign financial account — it must appear on the FBAR annually. Third, the mark-to-market PFIC election and the Article 17 SIPP election conflict — never make mark-to-market on PFIC positions inside a SIPP with an Article 17 election in place.
Jungle Tax | mailto:hello@jungletax.co.uk | 0333-8807974 | https://www.jungletax.co.uk
Article 17 defers US tax on SIPP growth under the US-UK treaty. It must be elected on Form 8833 annually — it does not carry forward. Missing it in any year triggers immediate US tax on that year’s SIPP growth.
Yes. A SIPP is a foreign financial account. Its peak market value must be reported on the FBAR for any year the aggregate foreign account balance exceeds $10,000. Omitting it is a material FBAR error.
RMDs begin at age 73 for those born after 1950. They must be taken by 31 December each year. The excise tax for missing an RMD is 25% of the amount missed — reduced to 10% if corrected within 2 years.
Not automatically. The UK does not always recognize this tax-exempt status. A specialist confirms the UK treatment based on your specific circumstances before you make contributions or conversions.
Yes — before arrival, where possible. The rollover is US-governed only if completed before arrival. Upon arrival in the UK, the rollover may have UK income tax implications. Complete it before the departure date.
No — it conflicts with the Article 17 treaty election that defers US tax on SIPP growth. Making mark-to-market inside the SIPP triggers current US tax, defeating the Article 17 deferral entirely.
