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.

Here’s why I think a SIPP might be better to build a £1m portfolio than a Stocks and Shares ISA

Our writer lays out three advantages a self-invested personal pension (SIPP) can have over an ISA when it comes to building a portfolio.

| More on:
happy senior couple using a laptop in their living room to look at their financial budgets

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.

Most investors have probably read that there are a growing number of Stocks and Shares ISA millionaires. But Hargreaves Lansdown revealed last year that the number of SIPP millionaires on its platform had jumped 20% in two years, from 3,166 to 3,794.

To be honest, this didn’t surprise me, as these DIY pensions have a few distinct advantages when it comes to building a sizeable investment portfolio. Here are three of them.

XXX

Government top-ups

Once someone pays into a SIPP, the government gives tax relief of 20%. Taxpayers on more than the basic rate can claim back more via self-assessment. 

For example, if I put £800 into my SIPP, the government automatically adds £200, bringing the total to £1,000. It normally appears a few weeks later. Because the government top-up is also invested, the portfolio can start to compound quickly, especially with regular contributions.  

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.

Uninterrupted compounding

It’s often said that investing is a marathon, not a sprint. This is true, and it plays into another key strength of the SIPP — investors can’t access money in it until the age of 55 (rising to 57 in 2028).

That has two immediate benefits. One is that it completely removes any temptation to take money out of the portfolio to spend on a new car, holiday, house renovation, dream wedding, emergency, whatever.

By contrast, a Stocks and Shares ISA is an easy-access platform. I can sell my shares at the push of a button, then have the cash sat in my bank account within days. But a SIPP prevents pot-dipping, assuming an investor is under 55. Of course, life does sometimes mean we need ready access to our savings, so the Stocks and Shares ISA has that advantage.

The second thing that’s excellent is its compounding process (interest being earned upon interest). Since I can’t touch the money early, it stays invested for longer. And the longer the compounding period, the bigger the final pot should be.

The first rule of compounding is to never interrupt it unnecessarily.

Charlie Munger

Fostering a long-term mentality

I’ve been investing in my own pension for a few years now. And because I intend to own the shares I have bought for potentially another two decades, my SIPP portfolio experiences far less churn than my ISA.

It also helps when I’ve to be patient with a particular investment. Take Shopify (NYSE: SHOP) for example. I’ve owned shares of the e-commerce enabler in my SIPP for many years.

However, I added to my holding in 2020 at what was (in hindsight) too high a value. In other words, I overpaid for my shares. Less than 18 months later, the stock had crashed 80% due to rising interest rates and my entire holding fell into the red.

It basically stayed that way for two years, as the chart below shows.

Yet during this period, the company continued growing its business and adding merchants to its platform. So instead of selling, I waited patiently for my position to recover (which it did last year) and I’m convinced the long duration nature of the SIPP fostered patience.

Shopify does face a lot of e-commerce competition, which is something I need to keep an eye on. But over 875m consumers — one in every six internet users — bought something from a Shopify merchant’s online store last year. That’s impressive, leaving me keen to remain a long-term shareholder.

Ben McPoland has positions in Shopify. The Motley Fool UK has recommended Hargreaves Lansdown Plc and Shopify. 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 »