The average ISA balance in the UK is £37,831 per holder, according to the latest HMRC figures. That’s up from £34,044 the year before, helped by rising share prices and a rush into cash ISAs. Here’s how the average ISA balance changes with age and income, and how to grow yours faster.
What Is the Average ISA Balance in the UK?
HMRC publishes ISA statistics every year. The latest figures, released in September 2026, show around 23 million adults held an ISA in 2023/24, with an average ISA balance of £37,831 each.
That average is pulled up by people with very large pots, so the typical saver has less. Plenty of people have a few thousand pounds in a cash ISA, while some long term investors have hundreds of thousands.
| ISA fact | Figure |
|---|---|
| Average value per ISA holder (2023/24) | £37,831 |
| Total value of all ISAs (2024/25) | £952 billion |
| Adult ISA accounts paid into (2024/25) | 16.8 million |
| Money paid in (2024/25) | £135.7 billion |
| Average paid in per account | Around £8,000 |
| Share of accounts that are cash ISAs | 64% |
Average ISA Balance by Age
Age makes a huge difference because older savers have had decades to pay in and let their money grow. HMRC’s figures show savers under 24 have around £11,087 on average, while those aged 66 and over have around £71,272.
Here’s a rough picture of how balances tend to build through life.
| Age | What’s typical |
|---|---|
| Under 25 | Around £11,000 on average, often in a Lifetime ISA or cash ISA |
| 25 to 44 | Balances growing, but often split with house deposits and childcare |
| 45 to 65 | Balances usually grow fastest as earnings peak and kids leave home |
| 66 and over | Around £71,000 on average |
Average ISA Balance by Income
You might think high earners dominate, but most ISA holders are on modest incomes. The middle ISA holder earns between £20,001 and £30,000, and people in that group have an average ISA balance of £34,575.
Holders earning £150,000 or more average £103,315. That gap comes down to being able to use more of the £20,000 yearly allowance, year after year.
Cash ISA vs Stocks and Shares ISA
Cash ISAs are more popular by number, making up 64% of accounts paid into. But stocks and shares ISAs hold more money, at 55.8% of the total value. That’s because invested money has grown faster over time than cash.
Over the long run, shares have historically beaten cash, although they can fall in value too. Our guide to the different types of ISAs helps you pick the right one.
Big ISA Changes Coming in April 2027
From 6 April 2027 the cash ISA limit drops to £12,000 a year for under 65s. The overall allowance stays at £20,000, so you can still put the other £8,000 into a stocks and shares ISA. Savers aged 65 and over keep the full £20,000 cash limit.
If you’ve been thinking about boosting your cash ISA, this tax year is your last chance to pay in the full £20,000 as cash. Here’s what to know about the ISA deadline.
How to Grow Your ISA Faster
1. Pay In Every Month
A regular monthly payment is easier than finding a big lump sum in March. Even £100 a month adds up to £1,200 a year before any growth.
2. Use Your Full Allowance If You Can
Any allowance you don’t use is lost when the tax year ends on 5 April. It doesn’t roll over.
3. Keep Fees Low
A cheap global index fund in a low cost platform can save you thousands over 20 years. See how to build a simple index fund portfolio.
4. Move Money From Taxable Accounts
If you’ve got savings or shares outside an ISA, you can shift them in each year. Our guide to the bed and ISA strategy explains how.
5. Let Compounding Do the Work
£200 a month at 5% a year grows to around £81,000 after 20 years, with about £33,000 of that being growth. Try your own numbers in our compound interest calculator.
Average ISA Balance FAQs
Is £20,000 in an ISA Good?
Yes. It’s more than many people have saved, and it’s a solid emergency fund or a great start to long term investing. It’s below the overall average ISA balance, but that figure is skewed by older savers with big pots.
How Many People Have £1 Million in an ISA?
Only a few thousand. Building a seven figure ISA usually takes decades of maxing out the allowance and investing in shares.
Do I Pay Tax on My ISA?
No. You pay no income tax on interest or dividends and no Capital Gains Tax on growth inside an ISA, and you don’t need to declare it on a tax return.
This article is part of our UK Investing Guide, where you will find every related article in one place.