Here’s how to build £300 monthly passive income streams by investing £20K now

Christopher Ruane outlines how he would use a £20k lump sum to try and earn hundreds of pounds monthly in passive income from blue-chip shares.

| More on:

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.

Close-up image depicting a woman in her 70s taking British bank notes from her colourful leather wallet.

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.

Buying into proven blue-chip companies is one way to earn passive income. It has worked for centuries and, while any given company is never guaranteed to pay out passive income in the form of dividends, I feel confident that building a diversified portfolio of high-quality, blue-chip shares ought to help me earn money without working for it, for years or even decades to come.

To illustrate, imagine I had a spare £20,000. Here is how I would use that to target £300 on average in passive income each month.

Doing the maths

How much one might earn from owning certain shares is fairly simple to work out, with the caveat that what happened in the past might not be a guide to what to expect in future.

We use something called dividend yield. Yield is basically how much I ought to earn per year in dividends as a percentage of what I invest.

So, if I invest £20,000 at a 7% yield (well above the FTSE 100 average but I think an achievable number in today’s market while sticking to blue-chip shares), I ought to earn £1,400 per year in dividends.

A watchout – and a game changer

As I said above, whether that happens depends on what companies choose to do with their dividends.

Not all companies pay dividends. Among those that do, some keep them level for many years in a row, some suddenly cut them, and others raise them regularly. So buying into the right companies will be critical to success in my passive income plan.

Still, £1,400 annually equates to dividend income of roughly £116 per month – welcome unearned cash, but little more than a third of my target.

So I would use a game-changing simple investment technique known as compounding. That means reinvesting my dividends so I can buy more shares and in turn hopefully earn more passive income. Doing that, after 14 years I ought to hit my monthly £300 target.

It’s important to find the right shares to buy, at the right price

What sort of shares would I be looking for to build that diversified portfolio with its average 7% yield?

An example of the sort of share I would consider is one I already own in my portfolio: Legal & General (LSE: LGEN).

The FTSE 100 financial services company operates in a market I expect to benefit over the long term from high customer demand. It can tap into that thanks to a number of competitive advantages. Those include an iconic brand, large customer base, and deep expertise in financial markets. It has also made moves in recent years to capture new, younger parts of the market, for example, by emphasising the social credentials of some of its investing.

There are risks. Legal & General cut its dividend during the 2008 financial crisis. A weak economy could again hurt markets, potentially hurting profits.

Making the first move

Still, with its 9% dividend yield, I think the share price reflects the risk. I see the current price as good value and continue to hold the shares.

How would I start with my passive income plan? My first move would be to put the £20,000 into a share-dealing account or Stocks and Shares ISA.

C Ruane has positions in Legal & General Group Plc. 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

Group of young friends toasting each other with beers in a pub
Investing Articles

FTSE 100 shares: has a once-a-decade chance to build wealth ended?

The FTSE 100 index has had a strong 2025. But that doesn't mean there might not still be some bargain…

Read more »

Passive income text with pin graph chart on business table
Investing Articles

I asked ChatGPT for its top passive income ideas for 2026 and it said…

Stephen Wright is looking for passive income ideas for 2026. But can asking artificial intelligence for insights offer anything valuable?

Read more »

Woman riding her old fashioned bicycle along the Beach Esplanade at Aberdeen, Scotland.
Investing Articles

Here’s how a 10-share SIPP could combine both growth and income opportunities!

Juggling the prospects of growth and dividend income within one SIPP can take some effort. Our writer shares his thoughts…

Read more »

Tabletop model of a bear sat on desk in front of monitors showing stock charts
Investing Articles

The stock market might crash in 2026. Here’s why I’m not worried

When Michael Burry forecasts a crash, the stock market takes notice. But do long-term investors actually need to worry about…

Read more »

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

Is this FTSE 250 retailer set for a dramatic recovery in 2026?

FTSE 250 retailer WH Smith is moving on from the accounting issues that have weighed on it in 2025. But…

Read more »

Young Black woman using a debit card at an ATM to withdraw money
Investing Articles

I’m racing to buy dirt cheap income stocks before it’s too late

Income stocks are set to have a terrific year in 2026 with multiple tailwinds supporting dividend growth. Here's what Zaven…

Read more »

ISA Individual Savings Account
Investing Articles

Aiming for a £1k passive income? Here’s how much you’d need in an ISA

Mark Hartley does the maths to calculate how much an investor would need in an ISA when aiming for a…

Read more »

Two business people sitting at cafe working on new project using laptop. Young businesswoman taking notes and businessman working on laptop computer.
Investing Articles

Is investing £5,000 enough to earn a £1,000 second income?

Want to start earning a second income in the stock market? Zaven Boyrazian breaks down how investors can aim to…

Read more »