Data from HM Revenue and Customs reveals that fifty children currently hold junior Individual Savings Accounts (ISAs) valued at over £350,000 each, highlighting a significant concentration of wealth in these tax-efficient savings vehicles. The average balance among the top 50 junior ISAs for the 2024/25 tax year stands at approximately £354,000.

According to figures obtained through a Freedom of Information request by RBC Brewin Dolphin, around 2,000 junior ISA accounts now contain six-figure sums. Junior ISAs allow parents, grandparents, and other relatives to deposit up to £9,000 annually into accounts that grow free of income tax and capital gains tax. Such accounts can hold cash or investments, with savings earmarked for children’s future use. Account holders can begin managing their funds at age 16 but cannot withdraw money until they reach 18.

Daniel Hough of RBC Brewin Dolphin explained that steady contributions over time can accumulate into substantial amounts, potentially providing financial support for major milestones such as university tuition or a first home purchase. Data for the current tax year shows that £2.5 billion was invested in junior ISAs, with 38 percent remaining in cash holdings. The average annual contribution is £1,570, reflecting a 16.6 percent increase compared to the previous year.

Assuming an average annual investment growth rate of 5 percent after fees, a child receiving this average yearly contribution from birth could have a junior ISA balance exceeding £45,500 by age 18. Full annual contributions of £9,000 could result in an account roughly worth £260,000 upon reaching adulthood, and in 2024/25, 108,000 junior ISA accounts received the maximum allowable payment.

The junior ISA scheme was introduced 15 years ago with a starting allowance of £3,600, which increased gradually to £4,368 by the 2019-20 tax year. A significant rise to a £9,000 allowance was implemented in 2020. However, analysts note that even consistently depositing the maximum amount since inception would require exceptional investment returns to match the value of the highest junior ISAs currently observed, suggesting some accounts have benefited from particularly strong market performance or early investments in high-growth assets.