For many investors, the magic of a Stocks and Shares ISA isn’t just picking winners — it’s the wrapper itself. Every tax year, account holders can put up to £20,000 into their ISA, sheltering dividends and gains from income tax and capital gains tax.
That matters more than it sounds. Over decades, the miracle of compounding means every pound saved in tax today becomes exponentially larger down the line.
From April 2027, the rules tighten: the cash allowance drops to £12,000 for under-65s, meaning anything above this will face a 22% charge on interest. So it’s preferable to maximise use of the £20,000 allowance, keep cash minimal, and let the shares deliver optimal returns.
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.
What £20,000 could become
If an investor had put £20,000 into a FTSE 100 tracker five years ago, total returns would be roughly 90% — turning £20,000 into about £38,000.
But the past five years have been good and we might not be that lucky in the next five.
Let’s assume a conservative 7% annual return going forward. Starting today with £20,000 and adding £5,000 each year for 20 years, the pot could grow to around £260,000.
With a more optimistic 9% return, it could exceed £340,000. The difference between 7% and 9% is £80,000, all tax-free inside the ISA.
Here’s a simple projection:
- £20,000 initial + £5,000/year for 20 years at 7% = ~ £260,000
- Same at 9% = ~ £340,000
- Extra £80,000 from just 2% higher returns
How to aim for higher returns
Aiming for 9% or higher isn’t entirely unrealistic. In fact, over the past decade, the FTSE 100 has averaged about 9% a year.
But some stocks have soared far higher.
The UK-listed defence contractor Babcock International (LSE:BAB) is a case in point. Over five years, its shares have returned 269% — well ahead of the average.
Its latest results reveal why — revenue climbed to £5,177m from £4,831m a year earlier, while operating profit was £305.1m, and the full-year dividend rose to 7.5p per share.
Management has reaffirmed medium-term guidance: mid-single-digit revenue growth, underlying margins of at least 9%, and cash conversion above 80%.
And with a £200m buyback programme in place, the company is clearly confident in the future.
Am I as confident?
Well, there are some risks to consider — not to mention the ethical question of investing in a weapons manufacturer. Ideally, most people would like to see global conflicts ease. But that means defence budgets would likely decrease, hurting Babcock’s profits.
And after such a strong run, the high valuation could limit further gains. So while I do think Babcock is worth a closer look, careful allocation sizing is important — I think around 4%-5% at most.
The bottom line
A Stocks and Shares ISA is one of the most popular ways to build wealth in the UK. Maximise allowance usage, minimise cash, and aim for a diversified mix of quality shares.
But whether you track an index or pick individual stocks like Babcock, the key is time in the market. Quick cash is usually a pipe dream – but if you’re patient, real long-term wealth is possible.
Should you invest £5,000 in Babcock International Group Plc right now?
When investing expert Mark Rogers and his team have a stock tip, it can pay to listen. After all, the flagship Twelfth Magpie Share Advisor newsletter he has run for nearly a decade has provided thousands of paying members with top stock recommendations from the UK and US markets.
And right now, Mark thinks there are 6 standout stocks that investors should consider buying. Want to see if Babcock International Group Plc made the list?
Mark Hartley does not hold any positions in the companies mentioned.
This story originally appeared on Motley Fool
