The secret habits of ISA millionaires
Financial Interest was founded by Damien Talks Money (389,000 YouTube subscribers) to teach the personal finance lessons he wished he'd been taught at school.
Last updated 25th February 2026
13 min read
There's something about the figure of one million pounds…
It's the entry-level number for being "rich", but not so outlandish that it feels Scrooge McDuck-levels of impossible.
And believe it or not, an increasing number of Brits are getting to the magic million mark in their ISAs alone. In fact:
- There are now more than 5,000 ISA millionaires in the UK
- The number of investors with seven-figure ISA pots has increased by over 1,000% in seven years
- The top 25 ISA investors are sitting on pots averaging £11,305,000.
We've pulled together research from UK brokers and Freedom of Information requests to find out how ISA millionaires achieved it – and how you can (or whether you should) borrow their habits.
Financial Interest provides guidance, not advice. If you’re unsure about anything, speak with a qualified adviser. When investing, your capital is always at risk. Past performance does not guarantee future results.
How much are most people saving in their ISAs?
Before we get to the ISA millionaires, it's worth asking: what does the average Brit actually have tucked away?
According to the latest government stats, we collectively hold around £872 billion in UK ISAs – more than at any point in history. A record £103 billion poured into adult ISAs in 2023-24 alone, and uptake hit its highest level in 13 years in September 2025.
On an individual level, the amount saved varies wildly – mainly according to income, age and location – with the average pot sitting at around £34,000.
As you can see, the patterns are pretty clear: the higher your income is, the older you are, and the wealthier your location is, the more you're likely to have saved.
The type of ISA you use also matters, though.
Across every income group, the data shows that the average balance in cash ISAs is significantly lower than in stocks & shares ISAs:
If looking at that graph feels a bit demoralising, it's important to bear in mind that the lower income bracket figures for stocks & shares ISAs are likely heavily influenced by pensioners who saved into a stocks & shares ISA for years prior to retiring (and now drawing a small income), or company owners whose income might look lower on paper.
That gap between stocks and cash shows up even more starkly when you zoom out to the market as a whole.
In total, stocks & shares ISAs now account for around £511bn of the ISA market, compared with £360bn held in cash ISAs. In other words, roughly 59% of total ISA market value sits in investments, and just 41% in cash – despite the fact that around 60% of all ISA subscriptions still go into cash ISAs.
But where are all our millionaires?
Although details on ISA millionaires don't appear in the publicly released figures (we'll get to that research in the next sections), interestingly, there are probably quite a few future seven-figure savers hidden in the above data. And in the words of the giant, disembodied hand from the 90s National Lottery Campaigns, it could be you.
Remember, ISAs have only been around since 1999, so no one in the UK has yet had the chance to take advantage of one out for a full working lifetime – but plenty will in the future.
Take a 25-year-old who already has £10,000 in their ISA – the average amount in the 25-34 age bracket. If they invest their money (rather than leaving it in cash) and manage to earn an average return of 7% a year, they could hit the magic million by investing £350 a month, every month, until they reach retirement age. Challenging? Yes. Comes with risk? Yes. Achievable? Also yes.
Now let's turn our attention to the real high-flyers: just how many people have managed to turn their ISAs into real fortunes – and what do we actually know about this exclusive club?
How many ISA millionaires are there, and how much do they have?
Since HMRC first started tracking seven-figure ISA holders in 2016, the numbers of ISA millionaires has risen every year through to 2023 (the most recent data available), with just a brief wobble during the pandemic.
At the last official count, there were 5,070 ISA millionaires — though most estimates suggest that number has by now climbed to at least 7,000.
Most ISA millionaires are, as you’d expect, hovering just above the million-pound mark. But a select few have managed to build genuinely extraordinary pots:
| ISA wealth bracket | Number of ISA millionaires |
|---|---|
| £1,000,000 - £1,999,999 | 4,800 |
| £2,000,000 - £2,999,999 | 200 |
| £3,000,000 - £3,999,999 | 30 |
| £4,000,000+ | 50 |
That top £4 million bracket would sit firmly in the "lucky (or exceptionally skilled)" category. To reach it, you'd need to have maxed out your ISA allowance every single year since ISAs were launched, and achieved an average return of 18% annually. That's well beyond what even most professional investors manage over decades.
In reality though, some of the earliest and largest ISA fortunes also owe a debt to history. Before ISAs, there were Personal Equity Plans (PEPs), launched back in 1986 and later merged into the ISA system. Older investors who maxed out their PEP allowances – and then continued the same habit with ISAs – gave themselves a serious head start on everyone else.
Take Lord John Lee, the first ever publicly declared ISA millionaire. A stock picker and Financial Times columnist, he reached the milestone on contributions of £126,200 over 16 years earning an annual average of 21% – having first built up a substantial PEP.
What ISA millionaires do differently
So, we know the numbers: how many ISA millionaires there are, how much they've managed to squirrel away, and just how steep the climb is to join their ranks. But numbers alone don’t tell the whole story.
What really matters – for anyone hoping to follow in their footsteps, or just curious about how the other half lives – is what these ISA millionaires actually do differently.
Let's take a look.
One thing ISA millionaires have in common is that almost all of them – 94% – reached their milestone through investing.
The remaining 6% used a combination of stocks & shares and cash.
This puts ISA millionaires in a very different camp from the average saver. For the rest of the UK, cash ISAs are about twice as popular as stocks & shares, and three-quarters of adults don’t invest at all outside their workplace pension.
Experts attribute this to the common perception that the stock market is too risky, while cash is the safer option.
However, in the past decade, the average return on cash ISAs has averaged just 1% – a return that doesn't even keep up with inflation. In contrast, the average returns for stocks & shares ISAs has been closer to 9% – outpacing inflation with a generous boost on top.
Of course, the standard investment warning applies: past performance is no guarantee of future returns, and the next decade may look very different. But the long-term trend is hard to ignore – broad, diversified investments have, historically, outperformed cash.
We should also note that many people save in cash because they feel they'll need the money in the short-term, compared to putting money away into the markets for the distant future.
It's also worth stating the obvious: most ISA millionaires didn't bet the house on stocks & shares straight out of the gate, and almost certainly had other financial building blocks in place first.
What's good for the goose isn't always good for the gander. Financial advisers would always suggest sorting the basics – emergency savings, pension contributions, and paying off high-interest debt – before throwing every spare penny into the market. ISA millionaires can afford to take risks because they've already covered the essentials.
They stick to a plan
It probably comes as no surprise that the vast majority of ISA millionaires max out their ISA allowance each year – and have done consistently since 1999.
But aspiring to join their ranks doesn't necessarily mean you have to do the same (though it would certainly help). What matters more is having an achievable, realistic strategy – and sticking to it, year after year. Patience plays a big part too: on average, it takes ISA millionaires around 22 years to reach their goal.
Even if you don’t have huge sums to invest each year, time and consistency can still do a lot of the heavy lifting.
Let's say you kick things off at 25, investing £200 a month. You keep it simple and put it all into a highly diversified index fund.
Returns are never guaranteed, but the global stock market has averaged returns of around 9% a year over the last few decades, so we'll use that as a guide.
Plug that into our handy compound interest calculator, and we can see you'd hit £1,000,000 after around 42 years – just in time to retire at 67.
If you doubled your contributions to £400 a month, it'd take you around seven years less to reach the same amount.
A more realistic approach might be to start small then increase your contributions as and when you can afford it. For example, start saving £100 a month now, and increase your contributions by 5% each year as how much you earn (hopefully) rises. Assuming 9% average returns again, you’d hit the big mill' in around 42 years.
Whatever your plan, unfortunately there aren't really any shortcuts unless you're loaded to begin with – which makes sense, considering the average ISA millionaire is 72.
They reinvest dividends
This is another hack that separates the millionaires from the nearly-theres.
Most funds come in two types: "income" (or dividend) and "accumulation". They hold exactly the same investments, but accumulation funds automatically reinvest dividends (the regular payouts you get for holding a fund) whereas income funds pay them out as cash.
This can make a huge difference, yet again because of compounding. Every reinvested dividend starts earning its own gains and dividends, which in turn get reinvested, creating a snowball effect.
For example, if you invested £10,000 into a fund that grows at 5% per year and pays 3% in annual dividends, you'd end up with £20,000 more in growth over 20 years by re-investing than if you'd taken the dividends as income.
Of course, some people need (or just like) the income, or choose to reinvest dividends manually – either back into the market or elsewhere.
Regardless of the method, reinvesting dividends can make an enormous difference long-term.
They don't trade a lot
It's easy to picture the typical stock market "winner" as someone glued to a screen full of charts and arrows, frantically buying and selling, sweat dripping onto their keyboard. But the research says the total opposite.
People who build wealth from investing tend to make careful choices, then hold onto them for dear life – even when the market's looking rough.
Over the last 30 years, if you'd put your money in the S&P 500 (a list of the 500 biggest publicly traded companies in the US) but missed just 10 of the best market days, you'd have ended up with half as much – and the best and worst days tend to happen close together.
Active trading is successful for an extremely small number of people – and they tend to work for major firms (rather than being youngsters selling courses and tips via Discord). It's harmful for most.
Something else sets ISA millionaires apart: they’re more likely to back the home team.
Both Hargreaves Lansdown and Charles Stanley report that their millionaire clients hold a higher proportion of UK-listed shares than the typical investor. Among HL's ISA millionaires, around 44% of portfolios are in UK assets, compared to 38% for everyone else. (For reference, the UK makes up just 5-7% of a typical global index fund.)
Why the home bias? It could partly be age: ISA millionaires tend to be older, possibly drawing income from their portfolios, and UK shares – dominated by banks, insurers, and other dividend-heavy sectors – offer better payouts. Or maybe it's just psychological comfort: it feels safer to invest in what you know.
Another quirk: both AJ Bell and Charles Stanley note their millionaire clients hold far more individual shares than the average investor.
That flies in the face of traditional investing advice of sticking to a well-diversified portfolio, but here, survivorship bias is probably at work. We're hearing from the people whose big stock picks paid off, not those whose would-be million-pound punts fizzled.
It's also a simple numbers game. When your portfolio's already in the hundreds of thousands, you can afford to take a punt on the odd left-field share without risking the whole pot.
For most of us, diversification – via funds and global exposure – is the safer, saner route. But it's still an interesting habit of those who've already hit the million mark.
When £1 million isn't what it used to be...
Of course, all of this is great if you’re already sitting on a sizeable pot and retirement's just around the corner. But what about younger savers, or anyone just starting out?
With inflation steadily eroding the value of money, a £1 million target in future might not be as out of reach as it once seemed – but it also won't buy what it does today. As salaries and costs rise together, you’ll need more than just a headline figure to secure the same lifestyle.
In fact, assuming inflation sits at 3% over the coming decades – above the Bank of England's target rate but closer to the UK's recent averages – a 25-year-old today would need to save over £3 million by retirement age to maintain the purchasing power of £1 million today, and even a 50-year-old will need an extra £500,000 or so:
| Age today | What £1 million is worth by age 65 |
|---|---|
| 25 | £3,262,037 |
| 30 | £2,813,862 |
| 35 | £2,427,262 |
| 40 | £2,093,777 |
| 45 | £1,806,111 |
| 50 | £1,557,967 |
| 55 | £1,343,916 |
| 60 | £1,159,274 |
And while the ISA allowance is supposed to rise with inflation, it's been stuck at £20,000 since 2017 and is now set to stay frozen until at least 2030. Over that period, prices have risen by around 35%, and the real value of the annual allowance has dropped by about £6,000.
The result is that younger (and even middle-aged) savers are being shortchanged, facing a far tougher task than previous generations if they want to build a pot with the same spending power. Add that to wages barely keeping pace with inflation, and it's clear the odds are stacked much higher than they used to be.
That said, by the time today's 20-somethings are reaching retirement age, the world might look very different. Maybe the ISA allowance will be £50,000, maybe salaries will auto-adjust for inflation in real time, and maybe and we'll all be commuting to work in flying cars (or, at the very least, driverless Ubers). We can hope.
Bottom line
So what’s the lesson behind all this? Mostly that becoming an ISA millionaire is a recipe with four ingredients:
- A decent amount to invest
- Time
- Patience
- Luck.
Most people fall short on at least one of those. Maybe you're not earning loads, maybe you dip in and out when life gets tricky, or maybe you panic‑sell in the next wobble. Welcome to being human.
The real trick is just showing up and doing the boring stuff, as often as you can, for as long as you can stomach it. Will you end up swimming in gold coins like Scrooge McDuck? Probably not. But will you be a lot better off than if you hadn't bothered? It's not guaranteed, but history suggests the odds are on your side.
Financial Interest provides guidance, not advice. If you’re unsure about anything, speak with a qualified adviser. When investing, your capital is always at risk. Past performance does not guarantee future results.
