The number of ISA millionaires has soared to a record high of 5,070, the latest annual figures show.

The figure has increased more than 1,000% in just seven years.

ISA millionaire numbers have now increased by 1,026% since 2016 when they stood at just 450.

An FOI request by money app Plum revealed the number of millionaires tracked by HMRC jumped almost 5% during the 2022-23 tax year from the 4,850 millionaires recorded the previous year.

According to HMRC’s data, the top 25 ISA investors are sitting on pots averaging £11,305,000 – up by £2.425m (27%) in the space of just 12 months.

Meanwhile, the average ISA millionaire is sitting on a pot of £1,346,000, virtually unchanged year-on-year.

Of the 5,070 ISA millionaires recorded in the figures, 4,800 investors were sitting on pots valued at £1m-£1,999,999, while 200 individuals had pots between £2m-£2,999,999 and 30 had pots £3m-£3,999,999. There were 50 investors with pots of more than £4m.

Rajan Lakhani of Plum, said: “The ISA millionaire club just got bigger, with 220 new members joining its ranks thanks in part to the US-driven AI-gold rush. Those at the top of the tree have - in some cases - seen their pots grow by more than £2m in the space of just 12 months, without a single penny of tax to pay on their gains.

“There’s no question that the rise of the so-called Magnificent Seven – Wall Street’s leading tech stocks including Nvidia - have helped balloon the pots of armchair investors here in the UK in recent years.”

He said since ISA millionaire numbers were first tracked in 2016, there’s only been a single annual dip recorded during that time, which was in 2020 when markets initially went into a major downturn at the beginning of the Covid-19 pandemic.

The rise and rise of ISA millionaires

*Millionaire numbers counted by HMRC on April 5 each year

Plum reckons that someone starting from scratch today, maxing out the current £20,000 annual allowance each year into a stocks & shares ISA could reasonably expect to reach millionaires’ row in around 22 years, assuming annualised returns of 7% after fees.