The transatlantic private client corridor has rarely been more active — or more technically demanding. At the PCD London Conference 2026, a panel of advisors examined the growing flow of wealthy Americans into the UK, the structural complexities their arrival creates, and the planning disciplines that separate successful outcomes from expensive mistakes.
The phenomenon has acquired a label: "Donald Dashers" — Americans departing the United States for political, fiscal, or lifestyle reasons. Graeme Privett, Partner at HaysMac LLP, reported that while the movement is real, it is narrower than media coverage suggests. Whilst politics has been a driver for many, personal choice and State taxes has driven many others. Americans resident in California or New York can face combined federal and state income tax rates approaching 50 percent on ordinary income. Leaving the US does not eliminate federal tax liability — American citizens pay US tax on worldwide income regardless of where they live — but it can remove State tax exposure. For a high-earning executive or entrepreneur, particularly one with a liquidity event on the horizon, that saving alone can be material. Moreover, whilst the UD federal government offers entrepreneurial tax relief on business gains under the QSBS system, not all States respect this and tax the gain in the usual fashion.
The Foreign Income and Gains (FIG) regime, introduced in April 2025 following the abolition of non-dom status, gives new UK residents (who have not been UK resident for the last 10 years) a four-year window during which their foreign income and gains are not subject to UK tax. For incoming Americans, this creates a genuine planning opportunity. Within that window, investment portfolios can be restructured out of US mutual funds and ETFs — which lack UK reporting status and create tax complications — and into vehicles that satisfy both US and UK requirements simultaneously.
Nick Wood, Partner at Sarasin & Partners LLP, described the challenge: it is not simply a matter of selling US investment vehicles and buying UK ones, because that creates its own US tax consequences, especially where PFICs are concerned (Passive Foreign Investment Companies). The four-year window requires careful sequencing, with each transaction considered in both contexts.
ISAs also present a particular trap. UK residents can invest in them, but from a US tax perspective there is no shelter — the income and gains derived from them flows through to US federal returns regardless. The same logic applies to SIPPs. Although their treatment under the US-UK tax treaty means regulated pension assets on both sides of the Atlantic generally receive reciprocal recognition, that does not necessarily mean that you can invest with impunity as administrative, regulatory and reporting restrictions can sometimes create other complications.
The path of least resistance, Wood suggested, is to invest US client portfolios in a way that is transparent and compliant across both jurisdictions. Investing in individual securities like bonds and equities, he noted, can sometimes be the simplest yet most flexible and efficient solution.
ISAs present a particular trap. UK residents can invest in them, but from a US tax perspective there is no shelter — the gains flow through to US federal returns regardless. The same logic applies to SIPPs, though their treatment under the US-UK tax treaty means regulated pension assets on both sides of the Atlantic generally receive reciprocal recognition. The path of least resistance, Wood suggested, is to invest pension assets in a way that is transparent and compliant across both systems.
David Sussman, Senior Director, Private Capital Services at JTC, brought a structural perspective. JTC operates across 24 countries and derives over 50 percent of its revenue from the US market, with domestic trust companies in Delaware, Wyoming, and South Dakota. The transatlantic corridor, in his view, is best approached as a planning exercise above all else. The mismatches between US and UK systems are extensive: citizenship versus residency as the basis for taxation, different fiscal year ends, different treatment of trusts, different approaches to estate duty. Getting the structure right before arrival — or departure — is not optional. It is the difference between a house built to withstand the storm and one that collapses under the first hurricane.
Sussman's metaphor was memorable. He builds houses for families. Tax specialists like Privett are the structural engineers who ensure the roof trusses will bear the load. Investment managers like Wood are the interior designers who make the house liveable and generate maximum utility from it. None of the three can function effectively without the others.
On the question of US citizens actually renouncing citizenship — which triggers a substantial exit tax and is an increasingly irreversible decision — the panel was largely dismissive of the trend. In Sussman's experience, of every hundred Americans who entertain the thought, perhaps five percent ultimately proceed. The cultural attachment to the US passport, even among the disillusioned, is deep. Those who do renounce tend to have done so after years of deliberate planning, holding multiple alternative passports, and satisfying themselves that there is no scenario under which they would want to return.
The panel's overarching message was as simple as it was demanding: plan early, plan comprehensively, and recognise that the US-UK intersection creates complexity that is not visible until it is already expensive. The FIG regime has extended the runway. Use it.
