Cash ISA
£20,000 annual allowance · typical return 4.5%
Annual allowance
£20,000
2025/26 tax year
Government bonus
None
—
Age eligibility
16+
UK residents
Typical return
4.5%
low risk
100% of the cross-wrapper £20,000 cap
Cash ISA vs other ISA wrappers
Annual subscription allowance comparison
Key insight
The Cash ISA offers a £20,000 annual subscription allowance for UK residents aged 16+. There is no government bonus — savers receive only the interest or investment growth from their own contributions. This wrapper sits in the low risk band; historical typical returns are 4.5%. Inside the wrapper, interest, dividends, and capital gains are exempt from UK Income Tax and Capital Gains Tax — no Self Assessment reporting required.
Compared to UK savings outside any ISA wrapper, the Cash ISA provides material tax-efficiency for higher-rate and additional-rate taxpayers; basic-rate taxpayers benefit primarily once their non-ISA interest exceeds the £1,000 Personal Savings Allowance. The Cash ISA sits alongside the other three ISA types (Cash, Stocks & Shares, Lifetime, Innovative Finance) sharing the overall £20,000 cap across all wrappers.
Derived from gov.uk Individual Savings Accounts + the HMRC ISA Manager Guidance Notes (2025/26 tax year). Additional context from HMRC ISA Statistics.
Rules at a glance
| Attribute | Cash ISA | Source |
|---|---|---|
| Annual allowance | £20,000 | gov.uk ISAs |
| Government bonus | None | HMRC ISA Manual |
| Age eligibility | 16+ | HMRC ISA Manager Guidance |
| Risk band | low | FCA Conduct of Business |
| Typical real return | 4.5% | FTSE Russell + ONS |
| Tax treatment | Interest, dividends, capital gains exempt from UK Income Tax and CGT | Income Tax Act 2007 s.694 |
Table sources: gov.uk Individual Savings Accounts, HMRC ISA Managers Guidance Notes, Income Tax Act 2007 s.694.
Frequently asked questions
Can I transfer between Cash ISA providers?
Yes. Use the receiving provider's transfer form. Transfers do NOT count against the £20,000 annual subscription allowance.
Can I subscribe to multiple Cash ISAs in one tax year?
Since 6 April 2024, you can subscribe to multiple ISAs of the same type within a single tax year (except LISA which remains one-per-year). The £20,000 overall cap still applies.
Disclaimer
PlainISA does not provide financial advice. For personalised guidance on which ISA wrapper suits your circumstances, consult an FCA-authorised financial adviser. See our methodology page for sourcing.
Browse all ISA types side-by-side or see our goal-mapped wrapper choice guide.