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.

Investing just £100 per week in a SIPP could help make me a multimillionaire

Stock market investing is done over long periods of time, which makes a SIPP a perfect choice for the creation of retirement wealth.

The words "what's your plan for retirement" written on chalkboard on pavement somewhere in London

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.

Investing in the stock market has proven to be one of the most reliable ways to build wealth, provided it is done correctly. And a self-invested personal pension (SIPP) is an excellent vehicle to do this in the UK.

A SIPP is a pension ‘wrapper’ that allows me to save, invest and build up a pot of money for my retirement. My contributions qualify for tax relief, meaning I automatically get a government top-up on anything I pay in (currently up to £60,000 per year).

XXX

So if I contribute £800, I’d get an extra £200, bringing the total to £1,000.

If I pay tax at a higher rate, I can claim more through my tax return. But for the purposes of this article, I’m going to keep the figures simple.

Needless to say, these extra top-ups can make an enormous difference in the long run. Indeed, as we’ll see, it means I could eventually retire with a very substantial sum.

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.

Investing in growth and income shares

Historically, the stock market has returned an annualised 8-10%. That includes stocks from both the UK and US markets, which generally have different characteristics.

The FTSE 100, for example, is dominated by old economy companies like banks, miners and housebuilders. Meanwhile, the S&P 500 is top-heavy with innovative tech giants like Microsoft.

But both kind of stocks can have a role to play in a thriving SIPP portfolio. The old economy firms often have stable market positions and pay attractive dividends.

Conversely, some tech stocks offer much higher growth potential but not much in the way of dividends.

Choosing one style completely over the other risks an imbalanced portfolio. My own SIPP is probably 60/40 in favour of growth stocks right now, but that’s my own personal preference.

My risk tolerance and approach will probably change as I get closer to retirement.

The maths

As mentioned, stock returns have averaged 8-10% per year over the very long term. There is no guarantee that will continue in future, but I don’t think a 10% return is a totally unrealistic goal to aim for.

After all, Warren Buffett has averaged 19.8% per year. If I can do basically half as well as him, I’d still be able to build up a nice nest egg.

In this scenario, then, my £100 a week would become £125 (or £6,500 per year) with the government top-ups. Achieving an average 10% return over 30 years, I’d end up with a final pot of £1,069,211 (excluding any platform fees).

To be honest, I find it incredible that investing a mere £100 a week in a SIPP could end up as £1.07m.

It could be even higher

Now, so far we have assumed that I start from scratch. But what if I put in a lump sum before I started investing regularly? What difference would that make? Quite a lot, actually.

The average person in the UK has £17,365 in their savings, according to the Building Society Association.

So if I invested this money in my SIPP at the start, then my final sum would be £1.37m, assuming the same average returns and government tax relief. That’s a huge £300,000 or so difference.

What if I kept this going for 35 years instead of 30?

Created at thecalculatorsite.com

As the chart above shows, I’d end up with a whopping £2.25m instead of £1.37m. And if I could invest £200 a week rather than £100, then I’d be looking at a very comfortable retirement indeed.

The lessons, then, are clear. Fuelled by compounding, my returns can just explode higher the longer I keep investing.

Ben McPoland has no position in any of the shares mentioned. The Motley Fool UK has recommended Microsoft. 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 »