The Junior Isa strategy that’s helped some accounts reach £200k

Hundreds of Junior ISA (Jisa) holders have built tax-free savings worth more than £100,000 – and around 50 children have more than £200,000 in their accounts.

A Jisa is a tax-free savings or investment account for under-18s, with up to £9,000 a year able to be paid in. Parents and guardians use them to give their children a financial head-start

Here Which? takes a look at these new figures, explains how these pots grow and whether a Jisa could be the right savings option for your family. 

Largest Junior ISA holdings

HMRC data obtained through a Freedom of Information request by financial advisory firm NFU Mutual shows just how large some Junior Isas have grown.

In 2022-23, around 1.25m accounts were open – up from 1.21m the year before. While most hold modest sums, a small group now have balances well into six figures:

• Around 680 young savers have between £90,000 and £99,999.
• Nearly 400 have between £100,000 and £109,999.
• 220 hold between £110,000 and £119,999.
• Around 50 children have more than £200,000 in their Jisas.

These are the biggest balances recorded since the product launched in 2011.

• Find out more: best Junior cash Isa rates 2025

How do Junior Isas work?

Junior Isas were launched in 2011 as a tax-free way to save or invest for a child’s future. A parent or guardian can open one, and anyone can contribute to it.

There are two types:

• Cash Junior Isa Works like a savings account, with interest paid tax-free.
• Stocks and shares Junior Isa Invests in funds, shares or bonds, with returns free from tax.

You can open one of each type for a child, and together they can hold up to £9,000 a year. Children can take control of the account from 16, but withdrawals aren’t allowed until they turn 18.

• Find out more: best junior investment Isas 2025

How to grow your child’s Junior Isa

The biggest Jisa pots have been built over years of consistent contributions and, in many cases, by choosing investments that deliver stronger growth.

HMRC data shows the average contribution in 2022-23 was £1,220, slightly down on the year before. Over 12 years, this would total around £14,000 – well below the six-figure balances seen in some accounts.

Families with the largest pots have made full use of the allowance each year. When Junior Isas launched in 2011, the annual limit was £3,600. It rose to £4,260 in 2018, £4,368 in 2019, and then jumped to £9,000 in 2020. By 2022-23, that could mean a total of £62,836 contributed.

Where the money is invested has also played a role. Around 42% of all Jisa balances are held in cash, but the strongest returns have generally come from stocks and shares Jisas. 

Cash Isa rates were low through most of the 2010s, averaging 1.7% to 1.9% between mid-2020 and mid-2022 before rising to 4.1% in 2024. The current average rate is 3.38%, according to Moneyfacts data. 

• Find out more: best children's savings accounts 2025

What are the best Junior Isa rates?

The highest Jisa rates come from smaller building societies. Bath Building Society offers 4.65% and Beverley 4.15%, but both deals are limited to local customers.

For accounts available nationwide, Darlington Building Society pays 3.75% and Mansfield 3.7%.

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3 ways to get the most from a Junior Isa 

If you want your child’s Jisa to work harder, there are a few simple strategies that can make a real difference over time. These approaches don’t just apply to six-figure pots – they can help maximise growth no matter the starting balance.

1. Maximise the allowance early

If you can, use as much of the £9,000 annual allowance as possible – and do it at the start of the tax year so the money benefits from a full year of growth.

If that’s not realistic, saving smaller amounts regularly through a standing order can still build the balance steadily.

2. Shop around for the best rate

Providers offer different returns, so check rates regularly. If you find a better deal, transfer the account through the new provider to keep the tax benefits. 

You can hold one cash Jisa and one stocks and shares Jisa at the same time, so there’s flexibility to split the balance.

3. Consider investing for the long term

Stocks and shares Jisas have the potential for higher long-term growth, especially over the 18-year term. 

Diversifying investments across different sectors or regions can help balance risk while still aiming for stronger returns.

Chris Hood, personal finance expert at NFU Mutual, said: 'Many families are missing out on potentially higher long-term returns by sticking with cash-based Junior Isas rather than investing in a stocks and shares Isa. 

'The figures show the potential for Jisas to grow into large sums when investments are given many years to mature and ride out short-term market volatility.'

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How else can children save?

If you've used up your child's tax-free options or you want to access the money before they turn 18, banks and building societies also offer non-Isa savings accounts for children. 

Children's regular savings accounts

If you can commit to monthly deposits, these accounts often offer competitive fixed interest rates on contributions (sometimes up to £200 a month). The discipline of regular saving can build a solid balance, but rates may drop after the first year.

The highest rate at the moment is from Penrith Building Society, paying 4.45% AER. 

Children's easy-access accounts

These accounts offer flexibility, allowing deposits and withdrawals at any time – a good choice if you want your child to manage their own money. Rates can be competitive, but they’re variable and often lower than fixed-term accounts.

Nationwide, Virgin Money and HSBC all offer accounts paying 5% AER right now. 

NS&I premium bonds

Premium bonds, run by government-backed National Savings & Investments, remain popular for children’s savings. 

Instead of earning interest, each £1 bond is entered into a monthly prize draw, with tax-free prizes ranging from £25 to £1 million. While there’s a chance of a big win, there’s no guaranteed return. 

The prize rate is currently 3.8% but will fall to 3.6% in August. The prize rate is the average return across all bondholders, based on the total value of prizes paid out. It is not a guaranteed rate, as winnings depend on luck. 

For every £1 you hold, you have a 22,000-to-1 chance of winning a prize each month.

• Find out more: should you get premium bonds?