ISA season is in full swing with the deadline fast approaching on 5 April. Investors just have one month to contribute to their maximum £20,000 Stocks and Shares ISA allowance. But is an ISA the right way to go?
There’s an alternative investment wrapper called a Self-Invested Personal Pension (SIPP), and that comes with brilliant tax breaks too. So I decided to ask artificial intelligence to sort out the pros and cons.
Please note that tax treatment depends on individual circumstances and may change in future. This article is for information only and does not constitute tax advice. Investors should carry out their own due diligence and seek professional guidance before making decisions.
I’m always wary of using ChatGPT. Some of its answers can be very iffy. But I thought it might be okay with a simple nuts and bolts question like this.
Comparing tax wrappers
The chatbot described ISAs as ‘refreshingly straightforward’. Investments grow free from income tax and capital gains tax, and withdrawals are tax-free too. ISAs are also flexible. Investors can take money whenever required.
By contrast, a SIPP gives tax relief on the way in. A basic-rate taxpayer who contributes £80 sees it topped up to £100. Higher-rate taxpayers can reclaim more through their tax return. “That instant boost can make a real difference over time”, the bot said.
There’s a trade-off. Pension savings are locked away until at least 55, rising to 57 from 2028. That makes a SIPP ideal for retirement planning but less useful for shorter-term goals, it said.
However, ChatGPT missed something which I’ll add now: SIPP withdrawals are also taxable, which they aren’t in an ISA.
After that AI sat on the fence, here’s my view. Personally, I see ISAs and SIPPs as partners rather than rivals. Someone sitting on a large Stocks and Shares ISA but a modest pension pot might decide to tilt new money towards a SIPP. The reverse can also apply.
Once the tax wrapper’s chosen, the fun begins: picking the right FTSE shares to fill it. And that’s where I part company with AI. It can summarise, but it can’t think. It can also hallucinate and get basic facts wrong.
GSK shares tempt me
One company I hold is GSK (LSE: GSK). The drugs giant is a FTSE 100 blue-chip with a long-term track record of growth and dividends. However, in recent years its star has slipped as its drugs pipeline dried. Now it’s on the mend. And it’s largely shrugged off worries about the Middle East.
Last month’s full-year results showed core operating profit climbed 8% to £9.7bn in 2025, while total operating profit almost doubled to £7.93bn. Over 12 months, the shares are up 45%.
There are risks with every stock. Growth’s expected to cool to between 3% and 5% in 2026 due to an HIV patent expiry and US pricing agreements. More than half GSK’s profits come from America, so tariffs and policy shifts remain a risk. Drug development’s costly and class action litigation an ever-present threat.
Today, GSK looks decent value on a price-to-earnings ratio of 12.3, plus a trailing yield of around 3.1%. I think it’s worth considering for those seeking long-term exposure to the healthcare sector. Whether in an ISA or a SIPP.
Others may prefer to target FTSE 100 shares that have been hammered by recent volatility, and are much cheaper as a result. There are plenty of those to choose from right now. Don’t hang around, that ISA deadline’s getting closer.
