Stocks and Shares ISAs
How investing inside an ISA works, what shapes returns, and charges and risk.
For information only, not financial advice.
Guides on investing through an ISA. Investments can go down as well as up, so you could get back less than you put in; the calculators show illustrations at returns you choose, not forecasts.
Quick answers
Can a stocks and shares ISA lose value?
Yes. The value of investments can go down as well as up, and an ISA does not change that: the ISA wrapper affects tax, not risk.
Is tax paid on income and gains inside a stocks and shares ISA?
gov.uk says you do not pay tax on income or capital gains from investments in an ISA.
Rules data last checked against gov.uk on 26 September 2026. For information only, not financial advice.
Tools for this topic
Stocks & Shares ISA Calculator
Estimate how investments could grow at an assumed return, with optional charges. Investments can go down as well as up.
Contribution Split Planner
Explore ways to divide contributions between cash and investments.
ISA Calculator
Estimate how a lump sum and monthly savings could grow, and see how much of this tax year's allowance is left.
Guides
- Cash ISA vs Stocks and Shares ISA: What Is the Difference?
How Cash ISAs and Stocks and Shares ISAs differ on risk, access, protection and the new cash ISA limit, with the points people weigh up.
- How Do You Split an ISA Allowance Between Cash and Shares?
How an ISA allowance can be divided between Cash and Stocks and Shares ISAs, what the rules say, and a worked example. General information only.
- Stocks and Shares ISA Average Return UK: What Investors Earn
What is the average stocks and shares ISA return in the UK? How fees, asset mix and time horizon shape returns, with a 20-year example. Not a forecast.
- ISA Investment Strategies for Beginners Explained
What pound-cost averaging, diversification and index funds are, how the ISA types differ, and why none removes investment risk. Information only.
- What Affects ISA Returns? Type, Timing, Charges, Allowance
How ISA type, contribution timing, charges and the annual allowance can affect an ISA's returns, with a worked example. Information only, not advice.
- Bed and ISA explained: moving existing shares into an ISA
How a bed and ISA works: selling shares held outside an ISA and buying them back inside, how it uses your £20,000 allowance and the CGT points to check.
- What Is an Innovative Finance ISA?
What an Innovative Finance ISA is, how it differs from cash and stocks and shares ISAs, and what gov.uk and the FSCS page say about tax, risk and transfers.
See also the ISA rules at a glance, the ISA glossary and all topics.