How I’m using my Stocks and Shares ISA allowance to aim to become a millionaire by 50

Henry Adefope outlines his action plan for achieving millionaire status by his early 50s through investing in his Stocks and Shares ISA.

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.

Young mixed-race couple sat on the beach looking out over the sea

Image source: Getty Images

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.

I have calculated that if I invest the maximum amount in my Stocks and Shares ISA for the next 20 years and achieve an average annual growth rate of 6%, I’ll reach ISA millionaire status comfortably. It’s an ambitious financial target for me, but a realistic one, nevertheless.

Becoming a millionaire is quite the accomplishment, and investing through an ISA can help me achieve this in less time by not having to pay income or capital gains.

To put myself in the position to be one in my early 50s, sticking to three investing basics will be crucial: investing early, maintaining or increasing my contributions, and staying invested during tough times.

An ambitious financial target like this requires a high risk appetite. For example, investing approximately £20,000  each year (£1,666.66 monthly)  with 6% annual growth would take me to just over £1 million in 25 years, whereas a 2% growth rate would get me there in 40 years.

Being in my early thirties, I figure having 100% equity exposure while I am still young gives me the greatest potential to maximise returns. Since I am investing for such a long time horizon, I can afford to take a high-risk approach.

My investment journey thus far

I am in my sixth year of investing and was fortunate enough to max out my ISA over the previous five years, which has resulted in a low six-figure ISA value for me currently. It is a high-risk portfolio that has returned 6.37% on an annualised basis, above the 6% growth target I require to reach my milestone.

The market over the last five years has been volatile, and I could have easily jumped ship when events like Brexit and the pandemic impacted the market. But I didn’t. And through remaining invested, I gain two benefits in relation to my financial objectives that I simply wouldn’t otherwise.

Dividend reinvestment is the first. The investment platform I use automatically reinvests any dividends paid from the shares I’ve bought, and this boosts my investment returns significantly — especially over time with compound interest.

Cheap diversification is the second — it is often the key to investment success. Aside from individual company shares, I have diversified exposure to different regions, sectors and assets through holding a range of investment trusts and funds that spread my risk.

I can’t predict how the market will behave over the next two decades, but committing to ride the highs and lows tends to provide a better result. The aim is to invest close to the maximum contribution every year while sticking to my aforementioned basic investment principles.

Of course, this will be as much as circumstances allow. Even if I fall short of the ISA limit every now and then, I should still be on track for my financial goal as a result of compound growth.

Ultimately my investment principles — combined with a bit of luck, timing and the right investment growth — should put me on the road to becoming an ISA millionaire by the time I’m in my early fifties.

Time will tell. 20 whole years of it.

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 using hiking poles, on a hike on a coastal path along the coastline of Cornwall. He is looking away from the camera at the view.
Investing Articles

Is Diageo quietly turning into a top dividend share like British American Tobacco?

Smoking may be dying out but British American Tobacco remains a top dividend share. Harvey Jones wonders if ailing spirits…

Read more »

Young woman holding up three fingers
Investing Articles

Just released: our 3 top income-focused stocks to consider buying in December [PREMIUM PICKS]

Our goal here is to highlight some of our past recommendations that we think are of particular interest today, due…

Read more »

Person holding magnifying glass over important document, reading the small print
Investing Articles

Tesco’s share price: is boring brilliant?

Tesco delivers steady profits, dividends, and market share gains. So is its share price undervaluing the resilience of Britain’s biggest…

Read more »

Businessman hand stacking money coins with virtual percentage icons
Investing Articles

1 huge takeaway from the Martin Lewis investing presentation

Martin Lewis showed how returns from stocks have smashed the returns from cash savings over the last decade. But here’s…

Read more »

Middle aged businesswoman using laptop while working from home
Investing For Beginners

I think the best days for Lloyds’ share price are over. Here’s why

Jon Smith explains why Lloyds' share price could come under increasing pressure over the coming year, with factors including a…

Read more »

A graph made of neon tubes in a room
Investing Articles

£5,000 invested in the FTSE 100 at the start of 2025 is now worth…

Looking to invest in the FTSE 100? Royston Wild believes buying individual shares could be the best way to target…

Read more »

Thoughtful man using his phone while riding on a train and looking through the window
Investing Articles

Can the BAE share price do it again in 2026?

The BAE share price has been in good form in 2025. But Paul Summers says a high valuation might be…

Read more »

Investing Articles

Can Rolls-Royce, Babcock, and BAE Systems shares do it all over again in 2026?

Harvey Jones examines whether BAE Systems and other defence-focused FTSE 100 stocks can continue to shoot the lights out in…

Read more »