This tiny error could wreck your bid to make a million from UK shares

If you want to make a million from investing in UK shares, you need to avoid mistakes. Like the one I’ve just spotted in my portfolio.

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.

If you want to make a million to fund your retirement, investing in UK shares is a great way to do it. By pumping regular sums into the stock market throughout your working life, you can amass a sizeable pot of money.

The trick is to leave it untouched to grow in value, year after year. So resist the temptation to raid your funds to cover spending, or panic and sell up in a stock market crash. Another thing you should do is invest in a Stocks and Shares ISA, because that way all your capital growth and dividend income is free of tax for life. It’s a huge perk for shareholders. 

There’s one more thing you must do. This one is vital, and I’ve just discovered I’m not always doing it. Please take a moment to check you aren’t making the same mistake too. Otherwise it could wreck your plans to make a million, or any other sum, from shares.

Make a million without slipping up

The key to building long-term wealth from UK shares is to reinvest all your dividends for growth. You should not take the money as income until you retire and really need it. Here’s why. Over the 20 years to 31 December 2019, the FTSE 100 index rose just 600 points to 7,542, a rise of just 8.8%.

If you’d reinvested all your dividends, your total return would have been 122%, figures from Schroders show. That’s an astonishing difference.

Dividends were particularly important in this period, because the FTSE 100 delivered such little growth, but it shows their long-term value. By reinvesting every penny, you’re often picking up shares when they’re cheap, after stock markets have fallen.

This means that to make a million you should reinvest every penny you get, but as I’ve just discovered, I haven’t been doing that.

Click to reinvest your dividends

I have money in a low-cost exchange traded fund, iShares Core FTSE 100 UCITS ETF. I thought all my dividends were being reinvested, but then I noticed I had built up a cash balance of £449.34. The dividends were sitting idle in my cash account earning zero interest, rather than being pumped back into FTSE 100 stocks.

This means that instead of buying the index during the crash in March, when it traded 20% lower than today, I bought nothing. That’s no way to make a million.

I’d forgotten to click the button on my trading platform that ensures all my dividends are automatically reinvested back into the stock or fund that paid them.

It took seconds to sort out. I went into the Dividend Reinvestment section, and amended my settings. Now all the money in my portfolio is going to work, rather than sitting idle.

I’m not great with technology, so you probably won’t make the same mistake. It’s worth checking though. It could be the difference between making a million and falling short.

Harvey Jones owns shares of iShares FTSE 100. 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

Warren Buffett at a Berkshire Hathaway AGM
Investing Articles

Warren Buffett profited massively from nervous markets. Here’s how!

With market turbulence making some investors nervous, our writer recalls several moments when Warren Buffett did well despite fearful markets.

Read more »

Close-up as a woman counts out modern British banknotes.
Investing Articles

How to target a 14%+ dividend yield by investing £10,000

There are many strategies for the average investor targeting a 14% dividend yield or higher. Our Foolish author explores one…

Read more »

Arrow symbol glowing amid black arrow symbols on black background.
Investing Articles

Up 6%, can this ‘gritty’ stock continue outperforming the rest of the FTSE 250?

ITV's share price is soaring as investors react to a resilient performance in 2025. The question is, can the FTSE…

Read more »

Investing Articles

How much income could £20k in a Stocks and Shares ISA give you today?

As the clock ticks on this year's Stocks and Shares ISA allowance, Harvey Jones looks at how investors could use…

Read more »

Investing Articles

What next for the Endeavour Mining share price after a record-breaking set of results?

Since March 2025, Endeavour Mining’s share price has risen 175%. Do the gold miner’s latest results provide any clues as…

Read more »

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

How are Rolls-Royce shares looking in March 2026?

March promises to be an interesting time for Rolls-Royce shares, but should investors be worried or calm about developments?

Read more »

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

3 these stocks are smashing BAE Systems shares – are they worth considering today? 

Harvey Jones looks at the impact of current events on BAE Systems shares this week, and highlights some FTSE 100…

Read more »

Santa Clara offices of NVIDIA
Investing Articles

At a forward P/E of 17, is Nvidia stock now a screaming buy?

Stephen Wright outlines why Nvidia stock could be better value now than it has been in a long time, despite…

Read more »