Over the summer, HMRC confirmed that every billionaire it can identify with a UK tax footprint now has a named Customer Compliance Manager. These are not clerks who process a return once a year. According to reporting by Bloomberg, their job is to build an “in-depth understanding” of each person’s finances and behaviour, review returns against domestic and foreign intelligence, and challenge anything HMRC believes is underpaid.
This follows the end of Britain’s centuries-old non-dom regime in April 2025, which had let wealthy residents avoid UK tax on foreign income. Since then, a line of well-known names has left: hedge-fund manager Chris Rokos, steel magnate Lakshmi Mittal, investor Nassef Sawiris and Betfred founder Fred Done, whose family reportedly paid about £400 million in UK tax last year.
It would be easy to read that and think: not my problem, I’m not a billionaire. I think that is the wrong conclusion, and the next hundred years of tax history suggest why.
Taxes aimed at the few end up reaching the many
Almost every broad tax in the developed world started life as a narrow one, pitched as a measure for the very top. Very few stayed there. Here is the pattern, in the two tax systems our members deal with most:
- 1913 · United States Federal income tax: 1% on income above $3,000 That threshold sat far above what most households earned, and fewer than 1 in 100 Americans paid. Within three decades, wartime financing had turned it into a tax paid by tens of millions.
- 1969 · United States The minimum tax, created after 155 high-income households paid no federal income tax It wasn’t indexed to inflation. By the 2000s it threatened millions of middle-class families, and Congress had to “patch” it year after year until it finally indexed the exemption in 2012.
- 1983 · United States Tax on Social Security benefits above $25,000 (single) and $32,000 (joint) Those thresholds have never been indexed. A levy that once touched a small share of retirees now reaches around half of them.
- 2013 · United States 3.8% Net Investment Income Tax above $200,000 / $250,000 Also not indexed. Every year of inflation quietly pulls more ordinary savers and landlords over the line.
- 2021 onward · United Kingdom Personal allowance frozen at £12,570; higher-rate threshold frozen at £50,270 The 40% rate was once a tax on the well-off. With the thresholds unmoved since April 2021 and wages rising, it now reaches teachers, nurses and police officers. The 45% threshold was cut from £150,000 to £125,140 in 2023.
- 2023–2027 · United Kingdom Allowances shrink, reliefs narrow The capital gains allowance fell from £12,300 to £3,000 and the dividend allowance from £2,000 to £500. Family farms and businesses lose full inheritance-tax relief above a cap from April 2026, and unused pensions come into inheritance tax from April 2027.
- 2025–2026 · United Kingdom Non-dom regime abolished; a named compliance manager for every billionaire This is where the current story sits: at the top of the pyramid, for now.
None of these started as a tax on the middle. Each was introduced, often sincerely, as a way to make the very wealthy pay their share. Each then spread for the same few reasons.
Thresholds that don’t move. Economists call it fiscal drag. Leave a threshold frozen while wages and asset prices rise with inflation, and more people cross it every year without any law being passed.
Allowances that shrink. Cutting an allowance rarely makes headlines, but it lands on every saver at once, not just the rich.
Machinery that gets pointed further down. Dedicated case managers, international data exchange and behavioural profiling don’t get switched off once they are built. They get cheaper to run, and the obvious next step is to use them on the next tier down.
Why billionaires leave first, and who pays when they do
Billionaires are among the most mobile people on earth. Dubai, Monaco, Switzerland, Italy and Malta compete openly for them. When the most mobile taxpayers leave, the revenue they took with them doesn’t disappear from the budget. It gets asked of the people who can’t move as easily: professionals, business owners, retirees with a house and a pension.
For scale, Britain’s wealthy population is estimated to have paid about £95 billion in income tax and National Insurance and a further £65 billion in other taxes in 2025–26. That is a broader group than billionaires alone, but it shows how much of the tax base sits with people who can, if pushed, choose to live somewhere else.
The other side of the argument deserves a fair hearing. Claims of a mass exodus are hard to measure and are sometimes overstated by people with an interest in overstating them. Governments point out that most wealthy residents stay, and they make a real fairness case for closing regimes like non-dom. Both things can be true. The point here isn’t that Britain is right or wrong. It is that the arithmetic puts the next bill on whoever is still standing where the tax collector can see them.
The risk was never in what you own. It is in where it sits.
What this means if you are not a billionaire
Nothing here is an argument for hiding anything. Everything we build is fully reported, and it has to be. The lesson is about concentration. Most people with meaningful savings hold almost all of it inside one country’s system: one tax authority, one set of rules, one currency, one political cycle. When that system decides it needs more, everything they own is in range at the same time.
The practical response is the same one we have written about before: spread across jurisdictions, legally and on the record, before you need to. Decide it in the calm years, not the year a new rule is announced.
The United States taxes its citizens on worldwide income wherever they live. Moving to Dubai, Cayman or anywhere else does not end U.S. tax obligations, and offshore holdings come with their own reporting rules. Jurisdictional diversification still matters for Americans, but for reasons of access, resilience and optionality, not as a way out of the IRS. Take proper advice before acting.