Gareth Hoyle · Founder & Editor
Reviewed May 2026. Independent researcher, not a financial adviser. About Gareth
A cash ISA gives you a known interest rate and FSCS protection. Your money is safe but grows slowly. A stocks & shares ISA aims for higher long-term growth, but values fall as well as rise and you could get back less than you put in. The deciding factor is usually how long you're investing for.
| Cash ISA | Stocks & shares ISA | |
|---|---|---|
| Risk to capital | Very low, protected | Higher, value can fall |
| Return potential | Lower, but certain | Higher over the long run, uncertain |
| FSCS protection | Yes, up to £85,000 | Against firm failure, not market loss |
| Best time horizon | 0–3 years | 5+ years |
| Inflation risk | Real value can erode | Historically beats inflation long-term |
| Effort | Set and forget | Pick investments / a ready-made portfolio |
Choose cash if…
- · You'll need the money within ~3 years
- · You can't tolerate any drop in value
- · It's your emergency fund or a house deposit soon
Choose stocks & shares if…
- · You're investing for 5+ years
- · You can leave it through market dips
- · You want a real chance to beat inflation
Why not both?
Plenty of people split their allowance: cash for the money they might need soon, investments for the long term. Try the Which ISA quiz or model the difference with our returns calculator.
Where to look
Cash ISA rates are competitive right now from fintechs (Trading 212, Moneybox, Plum) and banks alike. For stocks & shares ISAs, compare platforms like Fidelity, Hargreaves Lansdown, Trading 212 and InvestEngine on fees and fund choice.
Keep reading
Which ISA is right for me?
Answer a few questions and see which type of ISA tends to fit your goals, timeframe and risk appetite.
Returns calculator
Illustrate how cash, stocks & shares and peer-to-peer ISA returns could differ over time. Illustrative only.
Types of ISA explained
The five main types of ISA, how each works, who they suit and how they compare.
P2P ISA vs cash ISA
How an IFISA compares with a cash ISA on returns, risk, access and protection. Capital at risk vs FSCS-protected savings.