Turning a small ISA into a £500k portfolio

With a regular savings plan and a proper investment strategy, it’s possible to turn a small ISA into a formidable amount of money, says Edward Sheldon.

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.

Young black colleagues high-fiving each other at work

Image source: Getty Images

Investing within an ISA is one of the best ways to build wealth in the UK. With these tax-efficient accounts, even a small amount of money can turn into a larger sum over time.

Here, I’m going to explain how I’d aim to build a £500k portfolio if I was just starting my ISA journey today. These are the moves I’d make in an effort to build long-term wealth.

Please note that tax treatment depends on the individual circumstances of each client and may be subject to change in future. The content in this article is provided for information purposes only. It is not intended to be, neither does it constitute, any form of tax advice. Readers are responsible for carrying out their own due diligence and for obtaining professional advice before making any investment decisions.

I’d start with a savings plan

So, let’s say I already have a Stocks and Shares ISA open.

The first thing I’m going to do is start a regular savings strategy. Here, I’d sit down and work out how much I could afford to put into my ISA every month.

Then, I’d be disciplined and put this amount of money into my ISA account every month, the minute I was paid. ‘Paying myself first’ like this would help me save more effectively as I wouldn’t be tempted to spend the money.

Putting my money to work

Once the money was starting to pile up, I’d look to put it to work by investing it. This is the process of putting money into financial assets in the hope of generating greater returns than those offered by savings accounts.

Now, when it comes to assets that can grow wealth, it’s hard to beat the stock market.

Over the long term, the stock market has produced returns of around 7-10% per year for investors, making it the greatest wealth creation machine of all time. This performance from stocks has helped many people generate lasting wealth.

The key to successful investing

The thing is, to generate these kinds of returns, I’d need to build a proper stocks portfolio. I’m talking about a portfolio that’s diversified across many different companies, industries, and countries.

Without this level of diversification, I may not generate high returns.

For example, if I only owned four stocks, and one tanked, my overall returns could be low.

Similarly, if I had all my money in tech stocks, and the technology sector crashed, I could end up going backwards.

So, I’d do my research – with the help of experts like The Motley Fool – and set about building a diversified stocks portfolio that includes tech, healthcare, consumer goods, financial stocks, and more.

I’d aim to invest in world-class businesses such as Diageo (one of the biggest players in the alcoholic beverages market), London Stock Exchange Group, and Alphabet (Google’s owner), which all have incredible track records when it comes to generating shareholder wealth.

Aiming for £500k

How long would it take me to build up a £500k portfolio using this approach?

Well, it would depend on how much I was saving regularly and the long-term returns I was able to generate.

If I was able to save £1,000 per month and generate a return of 8.5% per year on my money over the long term, I could potentially hit the £500k mark in less than 20 years.

Ed Sheldon has positions in Alphabet, Diageo Plc, and London Stock Exchange Group Plc. The Motley Fool UK has recommended Alphabet and Diageo Plc. Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool’s board of directors. 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 tram in Manchester's city centre
Investing Articles

Here are 5 things Greggs shareholders just learned

Ben McPoland takes a look at some key bits from Greggs' 2025 report. But with consumer spending still under the…

Read more »

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

Lloyds’ share price has plunged 14% from its highs! Time to buy?

Lloyds' share price is back below 100p amid sinking market confidence. Should investors consider buying the FTSE 100 bank as…

Read more »

Landlady greets regular at real ale pub
Investing Articles

Prediction: in 12 months, Diageo shares and dividends could turn £20,000 into…

Diageo shares have dropped more than a quarter over the last year. Does this make the FTSE 100 company a…

Read more »

Investing Articles

Is today’s volatility a once-in-a-decade chance to buy UK stocks?

UK stocks are taking a beating as war in the Middle East spooks investors. Harvey Jones says investors need to…

Read more »

British coins and bank notes scattered on a surface
Investing Articles

How much do I need in an ISA to earn a second income of £950 a month?

A second income can be a life-saver when problems arise. Mark Hartley calculates how much is needed in an ISA…

Read more »

Rolls-Royce's Pearl 10X engine series
Investing Articles

Prediction: in 12 months, surging Rolls-Royce shares and dividends could turn £20,000 into…

Rolls-Royce shares have soared around two-thirds in value as earnings have continued to take off. Can it keep rising? Royston…

Read more »

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

After the FTSE 100’s latest slide, I spy bargain shares!

Since the US launched an attack on Iran, the FTSE 100 has dropped by over 5%. But falling share prices…

Read more »

Investing Articles

£10,000 buys 373 shares in this FTSE 100 heavyweight that’s tipped to surve in 2026

With analysts expecting the stock to climb 54% in the next 12 months, is now the perfect time for investors…

Read more »