How I’d invest £300 a month in a Stocks and Shares ISA to target £12k a year

Our writer outlines how a long-term investment approach could help him generate a sizeable passive income from his Stocks and Shares ISA.

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.

The Troat Inn on River Cherwell in Oxford. England

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.

Owning dividend shares is a time-tested way to build passive income streams. I do that using a Stocks and Shares ISA. By regularly drip-feeding money into it, I hope to build sizeable up a sizeable passive income over time.

As an example, if I wanted to target £1,000 each month on average in income (£12,000 per year), here is how I would go about it by putting aside £300 on a monthly basis.

Regular saving

My first move would be to get into a regular saving habit. That way, hopefully I would stick with it even when other other spending needs popped up.

Each person has their own individual financial circumstances. I think the important thing is to set a saving target that seems realistic given my specific situation.

I would put the money into a Stocks and Shares ISA from day one. That way, once I had saved enough money and knew what I wanted to invest in, I would be ready to act immediately.

Finding shares to buy

Investing is something I see as a long-term pursuit. So my plan to generate a four-figure monthly passive income from dividend shares would play out over decades not months.

That means that when buying shares, I will not be chasing the latest hot fad. Instead, I would hunt to find businesses I think have the foundations of profitability that could last for decades.

So I would look for companies in areas with large, resilient customer demand that have some competitive advantage. For example, the brands of Unilever, network of National Grid, and technology patents of Apple are all competitive advantages I think no rival could directly match.

I also look at a company’s balance sheet. If it is debt-heavy, that may reduce the prospect of dividends even if the business is profitable. After all, dividends are never guaranteed at any company.

Aiming for a target passive income

Another consideration is share price. That matters partly because the yield I earn on a share varies according to what I pay for it.

How much I need to invest to try and hit the £1,000 monthly target depends on the average yield of my portfolio. If that is 5%, for example, I would need £240,000 worth of investments in my Stocks and Shares ISA.

Reaching that by saving £300 each month would take 67 years. I could cut that time by more than half if I reinvest the dividends, something known as compounding. If I do that and continue to average a 5% yield, I could be earning £1,000 per month in dividends three decades from now.

On top of that, I would have a sizeable portfolio in my Stocks and Shares ISA. Depending on my choices, that could provide me with passive income for the rest of my life.

C Ruane has no position in any of the shares mentioned. The Motley Fool UK has recommended Apple and Unilever 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

Growth Shares

2 of the cheapest FTSE 100 stocks to consider buying as we hit 2026

Jon Smith calls out a couple of FTSE 100 companies that have fallen in the past year that he believes…

Read more »

Tesla building with tesla logo and two teslas in front
Investing Articles

Why Tesla stock outperformed the S&P 500 — again — in 2025

As the Tesla share price shrugs off declining revenues and profits to climb 19%, what kind of further excitement will…

Read more »

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

Thinking of investing in the stock market? Keep these basic rules in mind

Investing in the stock market can put investors on the fast track to building wealth and earning passive income. And…

Read more »

piggy bank, searching with binoculars
US Stock

This Dow Jones stock could be a dark horse outperformer for 2026

Jon Smith looks across the pond and spots a Dow Jones company that has fallen by 11% in the past…

Read more »

Investing Articles

Why Greggs shares crashed 40% in 2025

Greggs has more stores than it had a year ago and total sales are higher, so is a 40% discount…

Read more »

Man hanging in the balance over a log at seaside in Scotland
Investing Articles

4 pros and cons of buying Lloyds shares in 2026!

Investors piled into Lloyds shares last year as the bank delivered strong trading numbers in tough conditions. Could the FTSE…

Read more »

Investing Articles

Prediction: AI stocks will rise again in 2026 and Nvidia’s share price will soar to this level

Can Nvidia and other AI stocks continue to perform in 2026? Edward Sheldon believes so. Here, he explains why he’s…

Read more »

Chalkboard representation of risk versus reward on a pair of scales
Investing Articles

3 S&P 500 growth stocks that could make index funds looks silly over the next 5 years

Edward Sheldon believes these three high-flying S&P 500 stocks have the potential to smash the market over the next five…

Read more »