Gareth Hoyle · Founder & Editor
Reviewed May 2026. Independent researcher, not a financial adviser. About Gareth
Your £20,000 ISA allowance is "use it or lose it". Anything unused on 5 April is gone for good. Here's a quick checklist to run before the tax year ends.
Before 5 April
- Check what's left of your allowance with the allowance calculator.
- Top up if you can: even a last-minute cash ISA contribution locks in tax-free status for that money.
- Max the Lifetime ISA bonus: pay up to £4,000 in to earn the 25% government bonus (if eligible).
- Use both partners' allowances: a couple can shelter up to £40,000 between them.
- Open before you fund: if you're cutting it fine, opening the account early avoids missing the deadline.
While you're at it
- Review old ISAs for poor rates or high fees and consider a transfer.
- Check whether your current ISA is "flexible" before withdrawing anything.
- Think about next year: set up regular contributions from 6 April so you're not rushing again.
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.
ISA allowance calculator
Track how much of your £20,000 ISA allowance you've used across cash, stocks & shares, IFISA and Lifetime ISAs.
The £20,000 ISA allowance
How the annual ISA allowance works, splitting it across ISA types, and the rules that catch people out.
How to transfer an ISA
Step-by-step: how ISA transfers work, why you should never just withdraw, and how to avoid losing tax-free status.