Why this matters now
The UK is seeing a sharp rise in millionaire migration. Henley & Partners’ 2024 report projected a net outflow of 9,500 high-net-worth individuals (HNWIs), more than double 2023’s estimate of 4,200. Its 2025 report then forecast a record net loss of 16,500 HNWIs, the largest of any country this year.
At the same time, a small cohort funds a very large share of the Exchequer. HMRC’s latest projections show the top 1 percent of income taxpayers contribute around 28 to 31 percent of all Income Tax receipts, while the top 10 percent pay over 60 percent.
What the data says
- Scale and trend. Net HNWI outflows from the UK rose from an estimated 4,200 in 2023 to a projected 9,500 in 2024 and 16,500 in 2025. These are forecasts derived from wealth-migration data and expert inputs.
- Context and caveat. Critics note that even a “record” global movement still represents roughly 0.2 percent of the world’s millionaires, so headlines can overstate systemic risk if read without scale.
- Non-doms remain material. HMRC reports 60,800 UK-resident non-dom taxpayers in the tax year ending 2023, with 42,300 claiming the remittance basis. Policy shifts to a residence-based regime from April 2025 heighten behavioural uncertainty.
- Behavioural effects are real. The Office of Budget Responsibility, OBR, explicitly models migration, timing of realisations and income shifting when costing capital-tax measures. Policy design and signalling can therefore change location decisions at the margin.
Leadership risks for UK organisations
- Shrinking senior talent pool. Outflows compress the pipeline of experienced founders, CEOs, investors and NEDs who anchor boards, mentor scale-ups and professionalise governance. This elevates succession risk and lengthens critical executive searches in private and listed markets.
- Reduced density of leadership networks. London’s advantage has been proximity. If more HNWIs split residency or relocate, the informal deal-making and peer learning that accelerates leadership development thins out, especially in sectors like fintech, life sciences and private capital.
- Mentoring and philanthropy drag. Many HNWIs invest time and capital in universities, accelerators and charities. Departures reduce access to high-calibre mentors and impact capital that often seeds leadership programmes and spin-outs.
Company risks and operational spillovers
- Capital availability for growth. HNWIs are a meaningful source of venture capital and follow-on funding. Persistent outflows risk a higher cost of capital for early-stage and scale-up firms, and slower close times for rounds. It also slows M&A activity.
- Board effectiveness and continuity. Relocations can trigger director availability issues, time-zone friction, and potential re-domiciliation of holding companies, complicating regulatory oversight and committee coverage.
- Headquarter stickiness. If founders or controlling shareholders shift base, pressure can build to move group functions, IP ownership or treasury operations, with knock-on effects for UK employment and tax receipts.
- Tax-policy sensitivity. Concentration of receipts means departures or changed behaviour by a small group can have outsized effects on PAYE, CGT and dividend tax flows. HMRC and Commons Library data underline this concentration risk.
- Signalling effects. High-profile moves by prominent entrepreneurs can influence peers, lenders and later-stage investors, shaping perceptions of the UK’s competitiveness.
What is driving movement
- Perceived tax uncertainty. Debate over CGT, IHT and the non-dom regime has increased planning noise, and official forecasters acknowledge behaviour changes when incentives move.
- Portfolio and lifestyle diversification. Global mobility and multiple residencies are rising, with wealth owners optimising for time zone, schools, connectivity and sector ecosystems, not only tax.
- Comparative pull factors. Competitor hubs market clear regimes and concierge services for investors and founders. Henley highlights the relative pull of specific destinations in recent years.
How leaders and boards can respond
Leaders and organisations cannot control government or tax policy. However, there are steps leaders can take to mitigate the risks involve in the continuing shift coming from these decisions.
- Strengthen UK-based leadership pipelines. Invest in structured succession, executive development and NED bench building to lower dependency on a small circle of individuals.
- Broaden capital relationships. Build multi-channel access to UK institutional, corporate venture and international family-office capital to offset any local softening in angel density.
- Location strategy with guardrails. Where owners are internationally mobile, create a formal location-risk register covering directors’ availability, regulatory obligations, board calendars, and data governance. Many leaving the UK personally still have UK companies and directorships, so this is likely to be an area of regulatory focus if the forecasts materialise.
- Retention design. Use long-term incentive plans that are resilient to cross-border moves, with careful treatment of tax residence, vesting events and malus/clawback. Consider how flexible you can be as an organisation in your workplace to attract the best talent, even if they become more global.
- Stakeholder communication. If key leaders relocate, pre-empt market concerns with clear statements on HQ status, UK employment plans and compliance posture.
- Policy engagement. Industry groups should provide evidence on behavioural thresholds that risk tipping relocation decisions, to help calibrate reforms that protect the tax base without dampening growth. The scale caveat matters, but concentration of receipts means marginal changes still count.
What to watch through 2026
- Confirmed 2025 outturn vs forecasts. Track whether the projected net outflow of 16,500 materialises and which sectors are most affected.
- Implementation of the new residence-based rules. Monitor guidance, transitional reliefs and early behavioural data after April 2025.
- Receipts concentration. Keep an eye on HMRC updates to the top 1 percent and top 10 percent tax shares for 2024–25 and 2025–26.
Bottom line
The absolute share of millionaires who move is small in global terms, yet the UK’s projected outflows are large relative to peers, and the tax base is highly concentrated. That combination creates a real leadership and company risk profile: thinner senior talent density, potential pressure on early-stage capital, and greater volatility in receipts if a small number of high contributors change behaviour.
