The number of Isa millionaires has surged by more than 50% in a year, reaching approximately 7,730, according to figures obtained by money app Plum.
Plum secured the figure, rounded to the nearest 10, from HM Revenue and Customs (HMRC) following a freedom of information (FOI) request. HMRC reported that, as at April 5 2024, the estimated number of individuals with total Isa holdings of £1 million or more stood at 7,730.
52% jump in a single year
This marks a 52% jump, adding 2,660 new members to the Isa millionaires club, compared with 5,070 Isa millionaires recorded by April 2023. According to HMRC's latest response to Plum, the average Isa millionaire held a pot worth around £1,348,000 in April 2024.
The mean average market value of the top 25 Isa millionaire holdings was £11,928,000, rounded to the nearest £1,000. The majority of Isa millionaires, around 7,300, held amounts between £1,000,000 and £1,999,999 in April 2024, while approximately 60 had pots worth £4,000,000 or more. The average value of holdings among this group was £7,708,000.
HMRC caution and expert insights
HMRC cautioned that figures should be used as a “guide” because individual-level Isa data is provided annually by Isa managers, and each year a proportion may enter records incorrectly or fail to submit. Isas allow savers to boost their funds as accounts that are ringfenced from tax.
Will Bryant, director of wealth strategy at Plum, said: “A jump of more than 50% in a single year is really telling.” He noted that Isa millionaires are not people who “suddenly saved” their way to £1 million, highlighting the benefits of compound interest over time.
He added: “It’s the result of years of patient investing, where the growth on your growth starts doing the heavy lifting. That’s the bit people underestimate. These figures underline the value of investing and the importance of taking a long-term approach. Despite the geopolitical volatility of recent years, global markets powered by the US stock market have continued to climb.”
Future changes to Isa allowances
In April 2027, the annual cash Isa limit will be reduced from £20,000 to £12,000 for savers aged under 65, although the overall annual Isa allowance will remain at £20,000. The cash Isa allowance for people aged 65 and over will remain at £20,000. Mr Bryant said the changes “may lead people to use more of their stocks and shares Isa to make full use of their tax-free allowance,” but added: “Many people simply won’t know what’s changing.”
HMRC figures released in September showed around £135.7 billion was subscribed to adult Isas in the tax year 2024-25, a £32.7 billion annual increase. The increase was driven by a rise in cash Isa subscriptions, which grew by 37.5% or £26.1 billion. Stocks and shares Isa subscriptions saw a 19.7% or £6.1 billion annual increase, and Lifetime Isa subscriptions had a 20.1% or £472 million rise.
Maike Currie, vice president of personal finance at PensionBee, said: “Isas are one of Britain’s great savings success stories. Their beauty lies in their simplicity: a straightforward, tax-efficient way for ordinary people to build wealth and take greater control of their financial futures. And you don’t need to become an Isa millionaire to benefit.” Ms Currie said cutting the cash Isa allowance and introducing additional restrictions “risks making a simple product unnecessarily complicated, potentially undermining confidence at precisely the time we need more people saving and investing”.
