You won’t make a million with a Cash ISA! But £300 a month in a Stocks & Shares ISA may do it

I want to make a million from my hard-earned cash. Here I explain why I’m largely avoiding Cash ISAs and putting my money to work elsewhere.

The content of this article was relevant at the time of publishing. Circumstances change continuously and caution should therefore be exercised when relying upon any content contained within this article.

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More.

Want to get rich? Perhaps even make a million and retire early? It’s a dream that most of us have, and yet one that very few of us give ourselves a chance of realistically achieving. If you’re one of those people who simply lock their monthly savings up in something like a Cash ISA, I have bad news for you — you’ll likely be working right up until your mid-60s. Maybe even longer.

Forget about joining the millionaires club. Interest rates are so low on cash accounts that the prospect of making any sort of decent return is dead in the water. Ultra-low Bank of England base rates means that the yield on Cash ISAs is quite pathetic. And rates are in danger of falling further given the high chance of more rate cuts during the 2020s to support the UK economy.

Don’t despair, though. It’s pretty straightforward for the average Joe to make changes to their savings strategy with a view to getting rich and possibly even making that million. It means casting aside that Cash ISA and investing the bulk of your money in great UK shares via a Stocks and Shares ISA instead.

Couple relaxing on a beach in front of a sunset

Bad returns

Let me crunch some numbers to show you what you could be missing out on by sticking with a Cash ISA. Consider someone aged 30 who saves £300 a month, every month, up until the age of 65. Based on the best-paying rate of 0.9% today, that person would have made £148k.

It’s not too bad a figure at face value. But dig a little deeper and the pitfalls of the Cash ISA become apparent. For the £126,000 that the saver squirreled away over three-and-a-half decades they’d have made a paltry profit of just £21,939. In my book that seems to be a small return for half a lifetime of financial sacrifices and hard work. 

Make a million with UK shares

This is where the beauty of investing in UK shares comes in. Studies show us that the average long-term investor can expect to make a return of between 8% and 10% per year. Based on these figures, that person who invested £300 each month from the age of 30 to 65 would make a total return of between £643,000 and £1.02m. Yes, they really could have realised their goal to make a million.

Investing in a Stocks and Shares ISA improves your chances of becoming a millionaire with UK shares. These particular products save you having to pay anything to the taxman. And with a maximum annual investment allowance of £20k, these ISAs meet the needs of the vast majority of people.

We here at The Motley Fool believe that share investing is the best way to make your money work for you. The recent stock market crash provides a way to turbocharge the returns on your hard-earned savings too, by allowing you to buy UK shares at low prices and then watching them rise in value as the economic recovery takes hold. And there’s a wealth of top quality stocks out there to help you make a fortune.

Royston Wild has no position in any of the shares mentioned. The Motley Fool UK has no position in any of the shares mentioned. Views expressed on the companies mentioned in this article are those of the writer and therefore may differ from the official recommendations we make in our subscription services such as Share Advisor, Hidden Winners and Pro. Here at The Motley Fool we believe that considering a diverse range of insights makes us better investors.

More on Investing Articles

Mature black woman at home texting on her cell phone while sitting on the couch
Investing Articles

The FTSE 100 hits 10,000! What does this mean for investors?

The FTSE 100 -- the blue-chip stock index -- has reached an all-time high, representing a milestone for the supposedly…

Read more »

British coins and bank notes scattered on a surface
Investing Articles

How much do you need in an ISA for £2,026 passive income a month?

What kind of nest egg would an investor need for £2,026 monthly passive income? Our author crunches the numbers required…

Read more »

Warren Buffett at a Berkshire Hathaway AGM
Investing Articles

Warren Buffett has retired. Could his investing approach still work today?

Warren Buffett has handed over the reins at Berkshire Hathaway. He's been investing for decades and the world has changed.…

Read more »

ISA coins
Investing Articles

Got a spare £20k for a Stocks and Shares ISA? Here’s how it could generate a £1,400 passive income in 2026!

A Stocks and Shares ISA can be a serious source of long-term passive income. Christopher Ruane explains more about this…

Read more »

Growth Shares

2 of the cheapest FTSE stocks to consider buying as we hit 2026

Jon Smith calls out a couple of FTSE companies that have fallen in the past year that he believes are…

Read more »

Tesla building with tesla logo and two teslas in front
Investing Articles

Why Tesla stock outperformed the S&P 500 — again — in 2025

As the Tesla share price shrugs off declining revenues and profits to climb 19%, what kind of further excitement will…

Read more »

Black woman using smartphone at home, watching stock charts.
Investing Articles

Thinking of investing in the stock market? Keep these basic rules in mind

Investing in the stock market can put investors on the fast track to building wealth and earning passive income. And…

Read more »

piggy bank, searching with binoculars
US Stock

This Dow Jones stock could be a dark horse outperformer for 2026

Jon Smith looks across the pond and spots a Dow Jones company that has fallen by 11% in the past…

Read more »