Turning a £20k ISA allowance into £39,261 a year in passive income!

UK residents are able to use tax-free ISA accounts to generate wealth and passive income over the long run. Dr James Fox explains how.

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.

British bank notes and coins

Image source: Getty Images

Passive income is the holy grail of investing for many. And those of us who invest for passive income will likely be aware that using an ISA account can be hugely rewarding. That’s because the wrapper provides UK residences with tax breaks that allow us to maximise our investment returns.

So here’s how I’d target £39,261 a year in passive income.

Saving little and often

Firstly, I’d start by opening a Stocks and Shares ISA with a reputable broker, like Hargreaves Lansdown or Nutmeg. It only takes a matter of minutes and I can open an account with almost no money at all.

While many of us would love to start an ISA with £20K — the maximum annual allowance — in reality, most of us don’t have that amount of cash lying around.

So I may want to kick things off by committing to contribute a monthly figure to my portfolio. Even just £100 a month — or £3.30 a day — could be enough to get me on the path to earning passive income in the long run.

Over a year, that’s £1,200. I’d fall way inside the annual ISA allowance.

Although it’s worth noting that if I don’t have a lot of money to invest, it may be worthwhile choosing a platform with lower fees than Hargreaves. If I don’t invest regularly, I could pay as much as £11.95 per deal with Hargreaves. If I’m only buying £200 of stock, I don’t want to pay that much in commission.

And, to reiterate, I want to be doing all of this inside a Stocks and Shares ISA wrapper. That’s because no taxes are due on any of my returns, dividends, or share price gains. I get to keep everything I make.

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.

Passive income galore

If I don’t have much money, it can be hard to generate life-changing amounts of passive income. Instead, I need to take the dividends, or any returns, that I earn during the year and reinvest them, allowing my pot to grow bigger and bigger.

This strategy — called compound returns — complements regularly contributions, allowing the portfolio to grow faster each year as I start earning interest on my interest. No investment strategy is guaranteed, and the value of my stocks can fall as well as rise, but I’m a big fan of compounding.

As an investor on the FTSE 100, I can look to achieve anything up to 12% annually. But a more realistic figure is between 8% and 10%. A dividend-heavy portfolio might bring me a little less, say 6-8%.

Here’s how much passive income I could generate annually by investing just £100 a month.

6% returns8% returns10% returns12% returns
5 years£367.22£512.69£671.46£844.71
10 years£913.94£1,351.65£1,879.13£2,514.61
20 years£2,646.10£4,463.74£7,135.32£11,059.65
30 years£5,797.59£11,371.48£21,364.07£39,261.60

Of course, the rate of returns is just one of the key variables. I could contribute more, or even look to increase my contributions in line with inflation. And, naturally, the longer I leave my pot without touching it, the more funds I’ll have.

It would be remiss of me not to accept that £39,261 in 30 years won’t be worth the same as it is today and also that my returns aren’t guaranteed, since they may fall as well as rise. But it’s just an example using a relatively achievable contribution of just £3.30 a day.

James Fox has positions in Hargreaves Lansdown Plc. The Motley Fool UK has recommended Hargreaves Lansdown Plc. 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

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

Are investors running scared of Babcock and BAE Systems shares?

BAE Systems shares have had a brilliant run, and other UK defence stocks have been flying too. But Harvey Jones…

Read more »

Mature black woman at home texting on her cell phone while sitting on the couch
Investing Articles

As the FTSE 100 falls, savvy investors are looking for stocks to buy for the rebound

Many FTSE stocks have now fallen 10% or more from their 2026 highs. For long-term investors, exciting opportunities are emerging.

Read more »

Portrait Of Senior Couple Climbing Hill On Hike Through Countryside In Lake District UK Together
Investing Articles

Should investors consider buying resilient Admiral Group and Tesco shares as markets wobble?

Harvey Jones is impressed by how Tesco shares have held up in the current market volatility, while Admiral has been…

Read more »

DIVIDEND YIELD text written on a notebook with chart
Investing Articles

Down 15% in a month and yielding 7.5%! Should I buy even more of my favourite dividend stock?

Harvey Jones says this brilliant FTSE 100 dividend stock is suddenly cheaper due to recent market volatility. And the yield…

Read more »

Abstract bull climbing indicators on stock chart
Growth Shares

3 growth shares for an ISA that have beaten the FTSE 100 for the past 5 years

Jon Smith points out several growth shares that have outperformed the broader market over a long period of time, with…

Read more »

Calendar showing the date of 5th April on desk in a house
Investing Articles

Time’s running out for our 2025/26 Stocks and Shares ISA plans!

Never mind the stock market wobble, it's time to turn our attention to our Stocks and Shares ISA investments for…

Read more »

UK financial background: share prices and stock graph overlaid on an image of the Union Jack
Investing Articles

What might Warren Buffett think about today’s stock market?

Middle East conflict has given the UK stock market a bit of a hammering. But in the long-term scheme of…

Read more »

Man riding the bus alone
Dividend Shares

How big does my ISA need to be to make £2.5k in monthly passive income?

Jon Smith points out the key factors that go into building a dividend portfolio for passive income, and reviews one…

Read more »