How much extra income could a £20K ISA earn me?

Christopher Ruane runs his rule over what sort of extra income he could hopefully earn by putting £20,000 into the stock market.

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 mixed-race woman jumping for joy in a park with confetti falling around her

Image source: Getty Images

Different people earn extra income in a variety of ways. One common approach is to buy shares in companies that pay dividends.

But is that a realistic way to make a meaningful passive income stream in real life?

What drives income

Imagine I had £20,000 and put it in a Stocks and Shares ISA. I then use that to buy dividend shares. How much I could earn will depend on two things.

One is how much I invest. The second is the average dividend yield I earn. Yield basically means the annual extra income I would earn from dividends, as a percentage of the money I invest.

Digging deeper

But neither of those things is quite as straightforward as they may sound at first.

How much am I investing, for example? Putting £20,000 in makes it sound like that is all I am investing. It could be. But I also have the choice of reinvesting the dividends I earn in future, something known as compounding. That would mean I could invest more than £20,000 over time, without having to stump up more than my initial £20,000.

As for yield, that is not fixed. Dividends are never guaranteed. They can go up, but they can also go down, or be cancelled altogether.

By spreading my £20,000 over a range of different shares, I would limit the impact on my likely earnings if any one of them did poorly.

Still, a high yield when I buy does not always mean that I will earn that much down the line. If I had bought Persimmon last year when its percentage yield was in the mid teens, I would now be earning markedly less from it than I had expected after it cut its payout.

Focus on quality and valuation

That explains why I do not buy shares just because of their yield. Instead, I aim to buy shares in great businesses trading at an attractive valuation.

With generating extra income as my goal, I would also focus on companies I thought could generate substantial free cash flow to fund future dividends. So that would rule out businesses like Amazon and Alphabet, which currently reinvest profits inside their business rather than divvying them up among shareholders.

Setting expectations

I own some shares with percentage yields in the high single digits, like M&G and Altria. But a lot of dividend shares have a lower yield.

If I could hit an average of 7%, my £20,000 ISA could earn me an annual £1,400 in extra income. Simply by compounding dividends for a decade rather than taking them out of my ISA, I could then start to draw a higher annual income of £1,628.

That is not allowing for dividend increases in the meantime. Although dividends could fall or rise, hopefully if I invested in the right businesses at an attractive price, I may well benefit from growing dividends. My M&G shares, for example, paid me a 6% higher dividend per share this year than last year.

Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool’s board of directors. John Mackey, former CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool’s board of directors. C Ruane has positions in Alphabet, M&g Plc, and Persimmon Plc. The Motley Fool UK has recommended Alphabet and Amazon.com. 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 mature adult sitting by a fireplace in a living room at home. She is wearing a yellow cardigan and spectacles.
Investing Articles

How much is needed in an ISA to target a £766.60 weekly passive income?

Mark Hartley details why monthly contributions combined with high-yield stocks can help achieve passive income equivalent to the median UK…

Read more »

Stack of British pound coins falling on list of share prices
Investing Articles

After a 103% gain, this penny stock’s forecast to rise a further 106%. But will it?

Our writer was surprised to find this rallying penny stock's expected to grow even further, yet this one seems to…

Read more »

Young Black woman looking concerned while in front of her laptop
Investing Articles

Will the stock market finally crash next week?

The stock market has refused to crash despite all the uncertainty triggered by the war in Iran. But Harvey Jones…

Read more »

Three generation family are playing football together in a field. There are two boys, their father and their grandfather.
Investing Articles

No pension at 40? Don’t panic! A SIPP could be the answer

For those in their 40s who have yet to start saving, James Beard reckons there’s still time for a SIPP…

Read more »

Stacks of coins
Investing Articles

Potentially 58% undervalued, is this a penny stock bargain?

One analyst reckons this penny stock is 58% undervalued. James Beard wonders whether now’s the time to consider bagging himself…

Read more »

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

Here’s how a jittery stock market might help you retire years early!

When the stock market wobbles, some investors get nervous and panic. Others try to use the opportunities presented to their…

Read more »

Senior Adult Black Female Tourist Admiring London
Investing Articles

This 7.27%-yielding dividend stock is near a 52-week low! Time to consider buying?

Zaven Boyrazian has just spotted a dividend stock promising some big passive income for opportunistic investors. But is it too…

Read more »

Asian man looking concerned while studying paperwork at his desk in an office
Investing Articles

How to invest £5,000 to target a £400.50 second income

With many ways to earn a second income, one of my favourite strategies remains dividend shares. So which income stock's…

Read more »