Would taxing wealth make millionaires leave Britain?
The theory sounds obvious. The evidence is more interesting — and gives a sharper answer than a simple yes or no.
“If Britain shifts taxation away from income and towards wealth, wealthy people will leave the country.”
Some will. Most probably won’t. And whether the Treasury loses money depends far more on how the tax is designed than on whether any millionaires leave at all.
One thing worth stating up front, because almost every study below gets it wrong by omission: there is almost no direct evidence on a revenue-neutral switch from income to wealth taxation. Nearly every study — including every one cited on this page — examines a new wealth tax added on top of existing taxes, not a simultaneous cut to income tax alongside it. Reducing income taxes at the same time could materially change the result. That gap in the evidence is itself real, useful information — see the box near the end of this page.
Millionaire migration, as Henley & Partners reports it
This is the graphic behind the argument — and, on its own terms, it does not say what the argument claims it says.
Not an official statistic
These migration figures are private-sector estimates, not official government statistics — ONS and HMRC do not publish counts of millionaires entering or leaving the UK. They come from Henley & Partners (a residence/citizenship-by-investment advisory firm) and New World Wealth (a private wealth-research firm), who by their own account are "the only known independent wealth research entity" tracking this globally — meaning there is no independently published, corroborating source for these exact numbers. The methodology relies substantially on LinkedIn and other public work-location data, not confirmed tax residency or physical relocation records, and the destination-country lists reflect enquiry and application volumes, not measured migration counts.
UK net millionaire outflow, Henley/New World Wealth’s own estimate
-4,200
2023
-10,800
2024
-16,500
2025 (provisional)
Estimated wealth associated with the projected 2025 movers: ~$91.8bn — Henley’s own methodology states this is headcount × average per-capita wealth, not a sum of individually observed net worths, and movers will not necessarily bring all of it with them.
Where they say they’re looking — Henley’s own enquiry & programme data
These are Henley's own "most popular investment migration programs" and "Top 10 for enquiries" among UK citizens in 2025 — enquiry and application volumes, not measured bilateral migration counts.
Most popular investment-migration programmes
- Portugal
- Greece
- Italy
- Malta
Other top-10 enquiry destinations
- St Kitts and Nevis
- UAE
- Australia
- Cyprus
- Switzerland
- Austria
But the same source shows Switzerland gaining, not losing
Henley’s own figures project Switzerland to gain a net +3,000 millionaires in 2025 — one of the biggest gainers on the list — despite having raised recurrent wealth tax revenue worth around 1.03% of GDP (3.7% of total tax revenue, 2016, OECD) for decades. A wealth tax does not automatically make a country unattractive to the wealthy — the wider system matters at least as much as the existence of the tax itself.
Is this data reliable? An independent review has raised concerns.
An independent methodological review (Tax Policy Associates, July 2025) found the report's stated definition of "wealth" changed between its 2023 and 2025 editions (dropping property wealth entirely) without a corresponding change in the published millionaire counts, and identified statistical irregularities (an unusually low share of odd trailing digits across published figures) consistent with numbers "typed, not measured". The review's own conclusion stops short of proving fabrication — it says the figures could be fabricated, or could be a model's output manually adjusted for unknown reasons — and Henley & Partners (as distinct from New World Wealth, which supplies the underlying data) says it does not itself know New World Wealth's full methodology. New World Wealth's founder has attributed some of the patterns to rounding.
Henley itself does not present this as proof that UK tax changes caused the outflow — its own reporting names Brexit, economic opportunity, political stability, mobility, lifestyle, education and residence programmes alongside tax as drivers. Treat the map as context for the debate, not as evidence for any single cause.
What happens when wealthy people are taxed more
1. Britain has already run something close to this experiment
The 2017 reform brought long-term “non-doms” — UK residents for at least 15 of the previous 20 years — into the normal UK tax system, ending their access to more favourable tax treatment. This group is unusually internationally mobile, which is exactly why it is such a useful test case.
More people left than normal — but not a mass exodus
HMRC's own evaluation found normal churn (a comparison group unaffected by the change) was 4-5% more likely to leave; the affected long-term non-doms were 10-12% more likely to leave because of the reform.
Source: HMRC, "Evaluation of the change to UK Deemed domicile policy 2017"
Yet the Treasury made considerably more money
More than 9,800 (perhaps up to 15,600) affected taxpayers remained, contributing over £3bn/year — a lower-bound estimate, by HMRC's own admission. Additional revenue rose from £700m+ in the tax year ending 2018 to over £1bn in the tax year ending 2020.
Source: HMRC, "Evaluation of the change to UK Deemed domicile policy 2017"
Academic analysis HMRC itself cites found those who stayed ultimately paid around 155% more UK tax, and even those who emigrated saw their UK tax bill fall by around 60% — not to zero. People leaving does not automatically mean the policy loses money: the correct sum is tax gained from stayers, minus tax lost from leavers, minus avoidance/admin/economic effects.
A sourcing note, not a hedge: HMRC's evaluation, citing Advani, Burgherr & Summers (2024) — the team's own later (May 2025) working-paper draft, using a different specification, reports 50% and 73% respectively for closely related but non-identical quantities. Both are genuine findings from the same research programme; they are not interchangeable point estimates of one number.
2. Direct wealth-tax evidence: real, but modest in aggregate
The best available direct evidence on wealth taxes and migration comes from Swedish and Danish administrative tax and population data — not, as sometimes assumed, Norway. Researchers found that reversing wealth-tax cuts implies a 2% change in the stock of wealthy taxpayers for every 1 percentage point change in the top wealth-tax rate. The knock-on effects on the wider economy are small: employment -0.02%, investment -0.07%, value-added -0.1%.
Migration is real and measurable — but “the wealthy will all leave” is not what this evidence shows. Even the wealthy people who do leave don’t erase all the value they created: 45% of the businesses closed by an emigrating owner end up absorbed by other firms in the same economy.
Important asymmetry: This evidence comes from wealth-tax RATE CUTS (Sweden's 2006 repeal, two Danish reforms), not rate rises. The authors themselves state they "cannot rule out the possibility of asymmetric responses to tax increases vs. tax cuts" — and separately note that Sweden and Denmark, as small open economies, likely provide an upper bound on migration elasticities relative to larger economies like the UK.
3. The genuine danger zone: very mobile international wealth
Several Swiss cantons abolished a special “expenditure-based” tax regime for wealthy foreign residents who don’t work in Switzerland — a regime structurally similar to Britain’s old non-dom rules. The result: the stock of affected super-rich foreigners in those cantons fell around 43%, with no measurable response from Swiss-born wealthy residents, who were unaffected by the change.
Foreign, globally mobile multimillionaires are not the same population as ordinary British households with £1m–£5m in assets — the responsiveness of the very top of the wealth distribution is probably substantially higher than for the merely well-off.
A more precise mechanism than “people fled”: The authors' own draft describes the decline as driven mainly by redirected NEW ARRIVALS choosing cantons that still offered the regime, not by existing wealthy residents physically leaving — "the push-effect of the abolition seems to be rather small." This is a materially less dramatic mechanism than "people packed up and left." An earlier draft of this research reported 30%, not 43%, for this same finding — 43% is the final, published, peer-reviewed figure.
4. Spain’s warning: you don’t only lose the wealth tax
Spain’s regions set their own wealth-tax rates; Madrid has offered a 100% exemption for years — an internal tax haven. Five years on, Madrid’s stock of wealth-tax filers is around 10% higher relative to other regions. The design warning: personal-income-tax revenue lost from movers elsewhere in Spain was 6 times largerthan the direct wealth-tax revenue lost. You don’t only lose the wealth tax when somebody leaves — you often lose their income tax too, and by a bigger margin.
Two things worth knowing: The paper's own preferred explanation is that this is driven mainly by fraudulent residence DECLARATION ("evasion"), not physical relocation — its own words: "evasion is the dominant mechanism behind fiscal residence changes." Audit rates are higher for movers to Madrid specifically than for movers elsewhere, which the authors read as the tax authority itself suspecting fraudulent moves are concentrated there. And this is movement within Spain, not international emigration — This is a study of movement WITHIN Spain (between its autonomous regions), not international emigration — the paper explicitly checks and rules out "out-of-country migration" as a confound. A genuinely different phenomenon from the Swiss/Scandinavian international-migration evidence elsewhere on this page.
This "six times" figure is the paper's final, peer-reviewed (2025) result. An earlier (2020) working-paper draft of the same research reported the opposite conclusion at the national level — that national income-tax revenue "barely changes" due to this mobility. The research was evidently substantially reworked over the four-year peer-review process; the published figure is the one to use, though this site has not independently traced the calculation behind it (the full 2025 text is paywalled).
5. But Switzerland destroys the simple version of the story
Switzerland has raised recurrent wealth tax revenue worth around 1.03% of GDPfor decades — and by Henley’s own reckoning, it’s currently one of the biggest millionaire magnets in the world (see the map above). A wealth tax does not automatically make a country unattractive to the wealthy. The wider tax and economic system — stability, quality of life, rule of law, other taxes — matters at least as much as whether one particular tax exists.
6. “Shift income tax to wealth tax” is not the same as “tax the rich more”
Cutting income tax and raising wealth tax at the same time pushes in two different directions: a lower income tax attracts high-earning, economically active people; a higher wealth tax repels large accumulated fortunes. That could change which kindof wealthy person Britain attracts — from “already wealthy, low current income” towards “high-earning, wealth-creating” — which is a fundamentally different policy question from simply raising taxes on the rich across the board. Try the trade-off yourself: Tax Lab’s income↔wealth mix slider models exactly this shift — revenue-neutral on paper, honest about how little direct evidence exists on whether it would stay that way.
7. Why an annual 1% wealth tax is a bigger deal than it sounds
A flat annual rate sounds small next to income-tax headline rates — but it is levied on the whole stock of wealth, not the return it generates in a year, which makes it a much larger bite out of actual income than the percentage alone suggests.
| £10m in assets, at this annual return | Return | 1% wealth tax | Share of the return taken |
|---|---|---|---|
| 4% | £400,000 | £100,000 | 25% |
| 2% | £200,000 | £100,000 | 50% |
Recurring wealth taxes create stronger behavioural responses than the headline rate suggests — a problem that bites hardest on illiquid assets like businesses, farms and property, where there may be no spare cash to pay the bill at all (see this site’s land-tax-vs-farmers design problem for exactly this dynamic in a different tax).
8. The UK’s own Wealth Tax Commission takes a middle position
The Commission estimated a well-designed 1% annual wealth tax could reduce its own taxable base by around 7–17%through ALL behavioural responses combined — migration, avoidance, evasion, splitting assets, portfolio changes and reduced saving. That is not “7–17% of millionaires leave” — migration is only one part of a much broader response. At 0.18% above £500,000, it estimated this could raise around £10bn/year before administration costs.
IFS currently takes a more cautious line: We caution against introducing an annual wealth tax. Our view is that the government's priority should be to fix current taxes – including capital gains tax and inheritance tax. — but IFS itself does not oppose wealth taxation categorically — it separately says a credibly one-off wealth tax "could in principle be an economically efficient way to raise revenue, since tax liabilities based only on past wealth could not be reduced by changing future behaviour." Its objection is specifically to a recurring, annual wealth tax.
“An annual tax on stocks of wealth would penalise saving and create an incentive to move wealth out of the UK (or not bring it here in the first place)... quite how much the yield would be reduced is highly uncertain and contentious.” — Adam, S., Delestre, I. & Miller, H., "Options for tax increases" (IFS Green Budget 2025)
No need to be “wealth tax good” or “wealth tax impossible.” Try the design yourself: Tax Lab’s wealth-tax simulator.
If Britain cut income tax and raised an equivalent amount from taxing wealth instead — a revenue-neutral swap, not a new tax added on top — would the Treasury end up better or worse off overall, and would a different kind of wealthy person be attracted to or repelled from the UK?
Almost every empirical wealth-tax-migration study that exists — including the Scandinavian, Swiss and Spanish evidence used elsewhere on this site — examines a wealth or capital tax introduced, raised or abolished ON TOP OF an otherwise unchanged tax system, not a simultaneous, offsetting cut to income tax. A genuine swap creates two incentives pointing in opposite directions at once (a lower income tax attracts high-earning, economically active people; a higher wealth tax repels large accumulated fortunes), which could change WHICH kind of wealthy person the UK attracts, not just the net headcount — a qualitatively different question none of the single-direction studies is designed to answer. No country has been rigorously evaluated implementing a deliberate, revenue-neutral shift of this kind with administrative migration data before and after.
The proxy sometimes offered, and why it isn’t the answer
Commentators sometimes combine a wealth-tax-rise study (showing some migration) with a separate income-tax-cut study (showing some in-migration of high earners) to infer what a simultaneous swap would do.
The two estimates come from different countries, different time periods, different baseline tax systems and different populations — they are not simply additive. Critically, no such combination can show whether the swap changes WHICH kind of wealthy person the UK attracts (already-wealthy people with low current income, versus high-earning wealth-creators), which is a compositional question a headcount-only comparison cannot answer.
What would close it. A country implementing a deliberately revenue-neutral income-to-wealth tax shift, evaluated with the same quality of linked administrative tax and migration microdata Sweden, Denmark and Switzerland have provided for single-direction wealth-tax changes — or, short of a real policy to study, a structural model that can credibly separate the two offsetting incentives rather than simply summing existing single-direction elasticities.
So, would millionaires leave?
Some would — the evidence is clear that wealthy people respond to taxation, and the very richest and internationally mobile are particularly responsive. But the evidence does not support the idea of an inevitable mass exodus. Britain’s own 2017 non-dom reform caused additional departures, yet most affected taxpayers stayed and the Treasury raised substantially more revenue. International research similarly finds that higher wealth taxes reduce the wealthy resident population, but generally by a small fraction rather than causing wholesale flight. The bigger question is how the tax is designed. A recurring wealth tax added on top of already-high taxes carries materially greater risks than a broader reform that reduces taxes on earnings while shifting some taxation towards accumulated wealth. There is currently little direct evidence on that exact revenue-neutral trade.
Partly true, but misleading.
A more accurate version: higher wealth taxation would probably cause some wealthy people to leave. The empirical question is whether the tax lost from those departures exceeds the revenue gained from those who remain — and the evidence shows that it does not necessarily do so.
This is an editorial verdict on a general public argument, not a fact-check of one dated, attributed quote — it uses this site’s own canonical verdict vocabulary (see Fact checks) rather than inventing an attribution this claim, as a recurring theory rather than a single circulated statement, doesn’t have.