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ISAProject tax-free growth of a Stocks & Shares ISA over your horizon. Enter starting balance, monthly contribution (capped at £1,666/month to stay within the £20,000 allowance), expected return and fees.
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Three tax savings compound inside an ISA:
£20,000 per adult per tax year across all ISA types combined. Resets 6 April. Unused allowance does not carry forward. Lifetime ISA counts towards the £20,000 (max £4,000 LISA contribution).
SIPPs offer tax relief going IN; ISAs offer tax-free money coming OUT. If you expect to be in the same tax band at retirement, they produce equivalent results on contributions. Lower expected retirement band = SIPP wins; higher = ISA wins. See our Pension vs ISA calculator.
Depends on provider. A "flexible ISA" allows withdrawal and re-deposit without using allowance. Non-flexible withdrawals permanently use the allowance.
HMRC spots it from provider returns. The excess is removed, and in some cases penalties apply.
Yes. Since April 2024 you can also split across providers of the same type. The £20,000 total still applies.
Projections assume a fixed annual return — real markets do not return the same figure every year. Capital at risk. Past performance does not guarantee future results. General information only, not personalised financial advice.