Here are my 5 steps to try and become an ISA millionaire

From regularly rebalancing his portfolio to keeping on top of new stock ideas, Jonathan Smith outlines his steps to (hopefully) join the ranks of ISA millionaires.

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.

Some people might think that trying to become an ISA millionaire within their lifetime is completely impossible. I think it’s the tag of ‘millionaire’ that causes the issue. When I think about a million pounds, it’s a lot of money. But in my opinion, it’s obtainable. I would struggle to achieve this very quickly, of course, but over the course of a few decades, it’s definitely something I think could happen. Although some things are out of my control, here’s my five steps to trying to achieve this goal.

Working backwards

It might seem strange, but to begin with I actually need to look at the end scenario. Let’s say I want my Stocks and Shares ISA to be worth £1m in around 20 years time. If I assume an annual growth rate (that compounds) of 8% from the stocks I buy, then I can work out how much I need to start investing each month. Of course, I have to remember that the 8% return isn’t guaranteed.

In this scenario, it works out at around £1,500 per month. With the ISA allocation of £20,000 a year, this works. It could make me an ISA millionaire by year 22. This is an important starting point so that I can temper my expectations of what I need to do right now to help achieve my goal further down the line. 

The second step is then to start the process of investing £1,500 per month. If I can’t commit to this, then I can reduce the monthly amount, but in the knowledge that it’ll take me longer to get to the millionaire mark within my Stocks and Shares ISA.

Making progress over time

Third, I need to do ongoing research on the companies that I’m allocating my £1,500 to each month. As I mentioned, it’s not certain that I can achieve an average growth rate of 8% each year and it’s a big assumption that I will. A large part of making this happen is ensuring I pick good quality, sustainable businesses. It’s going to take me at least 20 years to reach my ISA millionaire status, so I at least want companies that’ll be still around.

The fourth step is to rebalance my stocks portfolio within my ISA over time. This is important as in the future, my ISA can become untidy and overly concentrated in a sector or industry. Trimming down some profits or allocating more funds to other companies is a good thing, and can help to keep my overall pot on track in the long term.

The final step is trying to be disciplined in letting my pot build up. I may have taken all the first four steps but then decide after a decade to pull money out for a house purchase or something else. There’s nothing wrong with this if I desperately need the money. But it will really set me back in my big target figure.

ISA millionaire potential

With discipline and a good game plan, I believe I can achieve my end goal. It will take years, but as the old saying goes, “the steeper the climb, the better the view”.

jonathansmith1 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

A senior man and his wife holding hands walking up a hill on a footpath looking away from the camera at the view. The fishing village of Polperro is behind them.
Investing Articles

ISA or SIPP? Here’s 1 advantage and 1 disadvantage of both

SIPPs and Stocks and Shares ISAs both have potentially attractive features, as well as downsides. Christopher Ruane looks at some…

Read more »

Portrait of pensive bearded senior looking on screen of laptop sitting at table with coffee cup.
Investing Articles

£1,000 invested in Lloyds shares 6 weeks ago is now worth…

Lloyds shares have been on a huge run in the last couple of years. But is a 15% pullback in…

Read more »

Man smiling and working on laptop
Investing Articles

After the FTSE 100’s slump, these bargain shares are calling!

Are you on the lookout for top cheap stocks to buy? Royston Wild reveals three FTSE 100 value shares he's…

Read more »

Man hanging in the balance over a log at seaside in Scotland
Investing Articles

Worried about a stock market crash? Here are 2 things you should know

A stock market crash may look plausible, but it’s far from a done deal. Still, if markets do wobble, I…

Read more »

piggy bank, searching with binoculars
Investing Articles

This FTSE 100 stock soared 900% — but after a 25% crash, is the rally over?

After blowing away the FTSE 100 in 2025, this miner has hit turbulence in 2026 — Andrew Mackie investigates what’s…

Read more »

A senior man and his wife holding hands walking up a hill on a footpath looking away from the camera at the view. The fishing village of Polperro is behind them.
Investing Articles

How much do I need in an ISA for a £700 second income?

Investing in dividend shares can be a great way to target a second income from a Stocks and Shares ISA.…

Read more »

Businessman with tablet, waiting at the train station platform
Investing Articles

If there’s a stock market crash this week, will you be ready?

Christopher Ruane explains why he's not phased by the inevitability of a stock market crash -- but is actively preparing…

Read more »

Mindful young woman breathing out with closed eyes, calming down in stressful situation, working on computer in modern kitchen.
Investing Articles

£15,000 invested in Diageo shares 3 weeks ago is now worth…

Bad times for Diageo shares! The last three weeks have seen yet another drop, but is this a time to…

Read more »