The number of UK residents with a personal fortune of at least GBP1 million fell by 7% in 2025 to 442,000, according to calculations by the Adam Smith Institute. This is the lowest figure since the 2008 global financial crisis. Compared to the peak in 2021, when the country had approximately 1.07 million millionaires, their number has decreased by about 59%.
For the purposes of the study, a millionaire is defined as an adult resident of the United Kingdom with a net worth of at least GBP1 million in constant 2025 prices. The calculation includes real estate, pension savings, cash, and investments, net of debt.
The Institute attributes the decline primarily to a decrease in the real value of assets. Post-pandemic interest rate hikes have put pressure on the value of pension savings and high-priced real estate, particularly in London. An additional factor is the low savings rate among British households, which limits the accumulation of private capital.
The study’s authors cite the departure of wealthy residents and the UK’s declining appeal to foreign entrepreneurs and investors as another reason. The Institute points to high tax rates, the abolition of the former “non-dom” tax regime, and discussions regarding new taxes on wealth and capital gains.
Effective April 6, 2025, the UK replaced the “non-dom” tax system with a new regime based on tax residency. New residents who have not lived in the country for the previous ten years may, for the first four years, receive an exemption from UK tax on foreign income and capital gains. After this period ends, the general rules apply to them.
The Adam Smith Institute also emphasizes that its data are estimates. The UK does not have an up-to-date government registry of personal wealth, so the indicator is calculated based on data from the Office for National Statistics and statistical modeling. It primarily reflects the general trend in changes to private wealth, rather than the exact number of wealthy residents.
The Institute has called on British authorities to abandon plans to introduce a wealth tax, lower the capital gains tax, and review the tax treatment of wealthy foreign residents. According to its data, the top 1% of British earners account for 29.1% of income tax revenue.
