We have some exciting news to share! The Motley Fool UK has now become The Twelfth Magpie -- an independent, UK-owned company, led by our long-serving UK management team — Mark Rogers, Chris Nials and Heather Adlington. In practical terms, it’s the same team you know, now fully focused on serving our UK readers and members.

Just as importantly, our approach remains unchanged: long-term, jargon-free, and on your side. This site is our new home, and there will be extra tweaks made across the coming few days as we settle in. So if anything looks a little off, please bear with us!

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.

How long would it take for an ISA to pay you £1,000 a month in passive income for life?

This writer shares how a Stocks and Shares ISA can deliver meaningful passive income over time, using steady contributions and long-term growth.

| More on:
Rear view image depicting a senior man in his 70s sitting on a bench leading down to the iconic Seven Sisters cliffs on the coastline of East Sussex, UK. The man is wearing casual clothing - blue denim jeans, a red checked shirt, navy blue gilet. The man is having a rest from hiking and his hiking pole is leaning up against the bench.

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.

Many investors dream of generating £1,000 per month in passive income without relying on a salary. Using a combination of consistent contributions, compounding growth, and careful planning, it’s achievable.

Crunching the numbers

To earn £12,000 per year in today’s money, the widely used 4% rule suggests a target portfolio of around £300,000. This is the balance needed to withdraw £1,000 a month indefinitely while maintaining purchasing power.

XXX

In practice, investors often start with smaller contributions and gradually increase them as income grows. Over a working life, this can accumulate roughly £250,000, a simple round figure to illustrate how consistent saving and compounding build wealth over time.

Using a lifetime ISA with realistic growth assumptions, the chart shows a 6% annual return reaching the target in about 22 years, while 8% returns get there in 20 years. Assuming a 25-year investing horizon provides a buffer against market shocks, such as stock market crashes.

Chart showing lifetime ISA contributions and the power of compounding

Chart generated by author

The key is sustainable withdrawals in retirement. Inflation steadily erodes purchasing power, so I adjust the £1,000 monthly income over time to maintain its real value.

At retirement, I assume returns drop to 4% to reduce risk once contributions stop. Even so, both scenarios leave a sizeable portfolio, which could support a long retirement or serve as a nest egg for children’s inheritance.

Dividend payer

With the target portfolio in reach, the next step is choosing investments that can sustain and grow income. One option is high-quality, dividend-paying FTSE 100 blue chips.

Legal & General (LSE: LGEN) might not have grabbed the headlines like peer Aviva last year, but its 8.2% dividend yield is exactly why it earns a place in my Stocks and Shares ISA.

On paper, things look a little alarming. Earnings barely cover the dividend, operating cash flow has been negative for the past two years, and traditional metrics raise concerns about sustainability.

But for insurance companies, traditional accounting numbers rarely tell the full story. Most profits are tied up in long-term products like annuities, so I focus on operating surplus generation (OSG). This forward-looking measure gives a clearer picture of sustainable dividends and long-term capital generation.

In 2026, dividends should grow by 2%, while OSG grows by around 5%, creating a healthier buffer for income-focused investors.

Of course, there are risks. Its large bond portfolio could come under pressure if inflation keeps pushing yields higher, potentially reducing OSG and delaying improvements in dividend cover.

Growth drivers

Looking long term, the insurer is well placed to capitalise on the growing pension risk transfer (PRT) market. Trustees of final salary pension schemes continue to rely on its expertise to derisk their portfolios. With markets remaining volatile, I don’t see this trend changing any time soon.

Over the next few years, the company expects to write £50bn-65bn of PRT, generating a steady, predictable stream of profits. That cash can then be deployed into its asset management division, adding another layer of income potential.

I own Legal & General for its passive income and long-term cash flow visibility, and it’s a stock I’m happy to hold. For investors chasing high-yielding, sustainable dividends, it’s certainly one worth considering.

Andrew Mackie 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

Friends and sisters exploring the outdoors together in Cornwall. They are standing with their arms around each other at the coast.
Investing Articles

£503 buys 14 shares in this FTSE 250 stock that returned 23.9% annually for the last 15 years

This FTSE 250 stock has averaged a huge return for 15 years. At today's price, £503 buys 14 shares. But…

Read more »

Black woman using loudspeaker to be heard
Investing Articles

£1,000 buys 25 shares in this FTSE 100 stock that’s returned 29.2% annually for the last 10 years

This FTSE 100 mining stock has returned close to 30% a year for a decade. At 3,995p, £1,000 buys 25…

Read more »

Female student sitting at the steps and using laptop
Investing Articles

Down 47%, is this growth stock finally worth buying in May?

With a £288m order book and a hidden pipeline of defence and nuclear contracts, is this growth stock now too…

Read more »

House models and one with REIT - standing for real estate investment trust - written on it.
Investing Articles

2 REITs yielding 7%+ to consider for passive income in 2026

A REIT backed by the NHS and another backed by Tesco and Sainsbury's with both yielding 7%+. Here's why I'm…

Read more »

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

Just 97 shares of this UK dividend stock generate £238 in passive income

A 5.7% yield, £238 in passive income from just 97 shares, and one of the most divisive dividend stocks on…

Read more »

ISA coins
Investing Articles

£10,000 in an ISA generates a second income of…

The London Stock Exchange is home to some of the world's most generous dividends. But how big a second income…

Read more »

Shot of a senior man drinking coffee and looking thoughtfully out of a window
Investing Articles

Expert recommendations: 2 top income stocks yielding 7%+!

With yields of 7.2% and 7.8% respectively, these two income stocks are catching the eyes of institutional analysts. Should investors…

Read more »

Illustration of flames over a black background
Investing Articles

3 top income-focused stocks to buy in May 2026, according to experts

Looking for a stock to buy for income in May 2026? Experts have flagged these three UK dividend shares as…

Read more »