The annual subscription allowance
Who this guide is for: For people deciding how much they can subscribe to ISAs in a tax year, and how unused allowance and transfers work.
- Step 1Check this year's allowance on GOV.UK
- Step 2Subscribe across permitted ISA types
- Step 3Unused room does not roll forward
- Step 4Transfers follow separate rules
Each tax year you can subscribe up to the overall ISA allowance published by HMRC for that year. Subscriptions across your ISAs normally share that single limit.
How the limit is used
- New money paid into ISAs counts toward the allowance.
- You choose how to split the allowance across permitted ISA types.
- Unused allowance does not roll forward to the next tax year.
Flexible ISAs and replacements
If your Cash ISA is flexible, withdrawals may be replaced in the same tax year without counting again toward the allowance — only where the provider supports flexibility.
Junior ISAs
Junior ISAs have a separate annual allowance for each child. Parental subscriptions still need to respect that Junior ISA limit. Confirm the current Junior ISA figure on GOV.UK alongside the adult allowance.
Compare a taxable disposal with assets held inside an ISA Use the Capital Gains Tax Calculator