UK ISA millionaires jumped 52 percent to 7730

The number of ISA millionaires in the UK rose by more than half in a single year to an estimated 7,730, according to HM Revenue and Customs figures obtained through a freedom of information request. As of April 2024, the average ISA millionaire held a pot worth around £1,348,000.

The count, released to the money app Plum and rounded to the nearest ten, represents a 52 percent increase on the 5,070 ISA millionaires recorded by April 2023 — 2,660 new members in twelve months. Around 7,300 hold between £1 million and £2 million; roughly 60 hold £4 million or more, with an average within that group of £7.7 million. The top 25 holdings average £11.9 million.

ISAs ringfence savings and investments from tax, and the arithmetic of membership is unglamorous: years of contributions in which, as Plum's director of wealth strategy Will Bryant put it, "the growth on your growth starts doing the heavy lifting." The surge tracks markets that kept climbing through years of geopolitical volatility, powered by the United States.

HMRC cautions that the figures are a guide: managers submit ISA data annually, and each year a proportion of records arrive incorrect or missing.

The wrapper is now being narrowed. From April 2027 the annual cash ISA limit falls from £20,000 to £12,000 for savers under 65; the overall allowance stays at £20,000, and the over-65s keep the full cash limit. Maike Currie, vice president of personal finance at PensionBee, said Isas are "one of Britain's great savings success stories" whose beauty lies in their simplicity — and that cutting the cash allowance and adding restrictions risks making a simple product unnecessarily complicated at precisely the time more people need to be saving.

In the 2024-25 tax year, around £135.7 billion was subscribed to adult ISAs, an increase of £32.7 billion, most of it into cash. From April 2027, savers under 65 will be allowed to put only £12,000 a year of it there.