A Stocks and Shares ISA lets you hold stocks, bonds, commodities and cash, all within a tax‑free wrapper. The annual allowance is £20,000, and any growth or dividends you earn inside it are free from income and capital‑gains tax.
That is a significant advantage, especially over 20-30 years.
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.
So why doesn’t everyone have one?
A big reason is that people don’t really know where to start. They hear about stock markets, crashes, crypto, and ‘once‑in‑a‑lifetime’ opportunities, and they freeze.
But there is no real downside to using an ISA to invest, beyond the usual risk that markets can fall. The main barrier is not the product — it’s the fear of things you don’t fully understand.
To make it easier, here are three useful things to do before you open your first ISA.
1. Write down realistic goals
Retiring in 10 years is a nice idea, but it only works if you know how to get there. How much can you put in each month? What would you have to cut back on to make it happen?
Start with something you can actually stick to, not a fantasy savings plan that leaves you broke by the end of the month.
2. Research realistic returns
Never assume a fixed return. Markets are unpredictable, and nothing is guaranteed. That said, history can help you set expectations. The FTSE 100 has delivered an annualised total return of nearly 8% since it started in 1984.
That does not mean it will return 8% every year; it could be 30% one year and a 10% loss the next. But over several decades, it tends to average out closer to that 8% figure.
3. Identify stocks with long‑term potential
Stock‑picking is hard, and news headlines often make every tech startup sound like the next Apple. In reality, the most reliable long‑term compounders are often pretty boring.
Think National Grid, Tesco or BT Group — household names that keep the country running. Alongside those, there are lesser-known businesses like Diploma (LSE: DPLM), which is one of my favourites.
A critical undercover company
Diploma makes controls, seals and diagnostics components for defence, agriculture, healthcare and industrial technology around the world.
Hundreds of thousands of people across the UK, Europe and North America use equipment fitted with Diploma parts every day, without ever knowing the company’s name. They do so through infrastructure such as power grids, water systems, hospitals and logistics networks.
With a market-cap of £8.72bn, it has, over the past 10 years, risen around 770% — the third‑highest return in the FTSE 100. That equates to an annualised gain of roughly 24.15% a year — far above the average for UK stocks.
The bottom line
Diploma is a strong option worth weighing up for a long-term ISA portfolio. It sits in those essential, often overlooked industries that quietly keep the world moving.
There is some risk from cyclicality in industrial demand, and there’s a chance it struggles to maintain such a high‑growth track record. But with earnings growth of about 43% year on year and a 19.7% return on equity (ROE), it looks good right now. And the price-to-earnings growth (PEG) ratio of 1.04 suggests it is fairly priced based on performance.
Still, diversifying investments across several sectors and regions helps offset volatility, so no single shock can wreck your plan.
