According to previously undisclosed figures, there are 2,000 ISA millionaires in the UK, with an average wealth of ?1,412,000.

The top 60 ISA billionaires in the UK now have pots averaging a staggering £6.2 million, according to official statistics released for the first time. The UK now has 2,000 ISA millionaires.

According to previously undisclosed figures, there are 2,000 ISA millionaires in the UK, with an average wealth of £1,412,000.

Total ISA millionaire holdings in the UK are currently at £2.8 billion, which means that assuming 7% annualised growth, those fortunate investors would get yearly tax-free gains of more than £200 million.

There are 60 investors in the £3 million+ range, and their combined average pot is £6,199,000.

A Stocks and Shares ISA owner with a wealth of £6 million may earn almost £434,000 yearly tax-free.

The announcement comes as "ISA season" approaches when savings institutions try to entice investors who haven't yet tapped into their yearly tax-free limit.

It is thought that all 2,000 wealthy ISA investors own Stocks & Shares ISAs. By maxing out their £20,000 yearly limit on the assumption of a compounded 7% annual return, investors beginning from zero today may expect to reach millionaires' row in around 22 years. The time required to reach the £3 million mark is 34 years, and 44 years to reach the £6 million club.

Given that Nigel Lawson first introduced ISAs (as PEPs) in 1987 with a £2,400 allocation (£6,400 in today's money), the information made public by HMRC suggests that only a small percentage of investors have reaped the rewards of supercharged gains over time.

There are now over 2.7 million S&S ISA holders, and 37% of them are using all of their available funds.

"Getting to ISA millionaire level is no easy achievement, so the fact that 2,000 people have managed to attain this reputation is really remarkable," says Laura Suter, head of personal finance at AJ Bell.

The members of this exclusive club will have had very significant investment returns in addition to using their annual ISA limit to the fullest.

However, a person who has contributed the maximum amount to their ISA each year since it was introduced in 1987 and who earns a consistent 5% return annually would have amassed a pot of just over £441,000 - far from becoming an ISA millionaire. Even if we consider someone who began saving in PEPs, the ISA's predecessor, and had done so while earning the same 5% return annually since PEPs originated in 1987, they would only have amassed close to £708,000 in their pot.

Everyone wishes they could go back in time and invest in the same types of investments that the top 60 club of ISA investors, who have an average of £6.2 million in their accounts, made. If we suppose they started when ISAs were introduced and invested the entire allotment, they would have needed to have earned 25% returns year on average ever since. To reach a pot of £6.2m today, they would still need to have generated returns of 15.5% annually even if we include PEPs. Truth is, these investors most likely placed a few really wise investments that saw significant value increases as well as a few more reliable returners.

(investingreviwes.co.uk, HMRC.co.uk, ajbell.co.uk)