A recap on the US private wealth landscape and what this means for future-proofing wealth management

The last two years have been rife with political change in the United States. President Trump's return to the White House and Zohran Mamdani's victory in New York's mayoral race have both added fresh momentum to debate around national and state-level tax policy and what it means for high-net-worth individuals (HNWIs) and ultra-high-net-worth individuals.

This debate is taking place against a backdrop of growing global wealth migration. According to the Henley & Partners Private Wealth Migration Report, 165,000 millionaires are expected to relocate internationally in 2026 – a record figure and further evidence that wealthy individuals are increasingly willing to consider alternative jurisdictions when the political or economic tides turn.

While predictions of a mass departure from the US haven’t so far materialised, there has been a noticeable uptick in US residents looking to relocate to the UK. In turn, this leads to conversations on whether existing structures and estate planning remain fit for purpose if family members, or businesses, become connected to multiple jurisdictions.

Against that backdrop, succession planning, trust/corporate structuring, and residence planning remains at the top of the private wealth agenda.

Political change is increasingly driving planning conversations

Political uncertainty has always influenced private wealth planning. What has changed is the extent to which it is shaping decision-making.

President Trump's return to office and wider political dissatisfaction has prompted renewed discussion around the future direction of federal tax policy. At state level, debate has become even more pronounced. In New York, Mayor Zohran Mamdani has championed proposals including a 2% increase in income tax for individuals earning more than $1 million annually, alongside broader calls for higher taxation of wealthy residents and the ‘pied-a-terre tax’ – a form of mansion tax. Meanwhile, California has continued to see debate around a proposed billionaire tax, including a one-off levy on individuals with net assets exceeding $1 billion.

The United States also presents a more nuanced picture than headlines around wealth migration often suggest. At a national level, the country remains the world's dominant wealth hub, home to more than 250,000 ultra-high-net-worth individuals and accounting for 41% of global UHNWI growth. At the same time, a domestic migration pattern is unfolding within the country, with individuals leaving high-tax states such as California and New York for jurisdictions including Florida, Texas and Arizona.

For many, concerns stem from what will happen - not what is happening right now.

Existing structures under the microscope

One consequence of this uncertainty is that many families are undertaking a detailed review of existing planning structures.

For example, it’s common for US families to have established trusts (revocable and irrevocable), LLCs and other family holding structures as part of domestic estate and succession planning. While effective in the US context, this could change significantly if family members later become resident elsewhere or acquire assets in another jurisdiction.

Trusts, family investment structures (and different types of investments themselves), and succession plans that were designed for a purely domestic US family may not produce the same outcome where beneficiaries become internationally mobile or where assets are held across multiple jurisdictions.

The more significant trend is therefore not migration itself, but preparation. Many families are carrying out what amounts to a health check of existing arrangements to ensure they remain effective if circumstances change.

The UK opportunity and the need for careful planning

For some internationally mobile families, the UK continues to feature in long-term planning discussions.

However, the landscape has changed significantly following the abolition of the non-dom regime and the introduction of the new four-year foreign income and gains (FIG) regime. While the new rules create opportunities for some individuals relocating to the UK, they also increase the importance of reviewing existing structures before a move takes place (as well as the need for those US connected individuals to review their planning if they have had a presence in the UK historically).

This is particularly relevant for US citizens. Unlike most jurisdictions, the US taxes its citizens on their worldwide income regardless of where they live/ are tax resident. A favourable outcome in the UK may not necessarily produce the same result from a US tax perspective.

For example, a US citizen relocating to London may benefit from the UK's FIG regime in relation to overseas income and gains. However, those same amounts may still need to be reported in the US and could remain subject to US taxation (subject to the US/UK double tax treaty). Equally, certain US investments do not qualify for the FIG regime.

The planning exercise is therefore not simply about understanding UK rules. It is about understanding how UK and US tax systems interact.

Looking ahead to the November midterms

As attention turns to the November midterm elections, HNWIs will be watching closely for signals on future tax policy.

The last two years have demonstrated that political developments don’t need to result in immediate legislative change to influence planning decisions. The prospect of wealth taxes or wider reform affecting wealthy individuals is enough to shape conversations.

For internationally mobile families, the objective is not necessarily to predict the next political development. It is to ensure that existing arrangements are sufficiently flexible to respond when change comes.