The number of UK residents with personal wealth of at least £1 million fell by 7% in 2025 to 442,000 people. This is the lowest figure since the global financial crisis of 2008, according to updated calculations by the Adam Smith Institute.
Compared with the peak in 2021, when the country had around 1.07 million “sterling” millionaires, their number has decreased by approximately 59%. The decline has been observed for the fourth consecutive year: after the number of millionaires first exceeded one million in 2020, the figure began to fall steadily.
In the study, a millionaire is defined as an adult UK resident whose net asset value is at least £1 million in constant 2025 prices. The calculation includes property, pension savings, cash and investments minus debts. The estimate is based on data from the Office for National Statistics (ONS) and uses a Pareto distribution model, as the UK has no up-to-date register of personal wealth — the official Wealth and Assets Survey is conducted only once every two years.
The Adam Smith Institute identifies three main factors behind the decline.
Falling real asset values. Higher interest rates and weak confidence in the British economy have reduced the inflation-adjusted value of pension pots and high-end property, particularly in London.
Outflow of wealthy individuals. High-net-worth residents are either leaving the country or choosing not to move there. Reasons include the abolition of non-dom status in April 2025, high levels of taxation, the threat of a wealth tax, and a “culture hostile to wealth creators.”
The Institute emphasises that millionaires make a disproportionately large contribution to the budget: the top 1% of taxpayers account for around 29.1% of income tax receipts.
Institute economist Mitchell Palmer said: “The decline in the number of millionaires may be greeted as a success by some on the Left, but it should instead be viewed as a warning signal. Every millionaire that leaves mean less capital for British businesses, fewer international connections, and a weaker entrepreneurial spirit.”
Shadow Business Secretary Andrew Griffith noted that the loss of millionaires hits tax revenues and job creation. In a competitive world, he said, the departure of ambitious people is “a shameful sign.”