A Cash ISA is an Individual Savings Account that holds cash savings and pays interest that is normally free from UK income tax.
Cash ISA in plain English
A Cash ISA is like a savings account with a tax wrapper around it. You put cash in, the provider pays interest, and that interest is normally free from UK income tax.
Cash ISAs can be useful when you want to keep money stable and accessible. They are often used for emergency savings, short-term goals, house deposit savings, tax bills, planned spending or money you do not want exposed to investment risk.
A Cash ISA is different from a Stocks and Shares ISA. A Cash ISA holds cash and pays savings interest. A Stocks and Shares ISA can hold investments, which may grow more over the long term but can also fall in value.
For the 2026/27 tax year, the overall ISA allowance is £20,000. You can use that allowance in one ISA or split it across different ISA types, subject to the rules for each type.
From 6 April 2027, the government has announced that the annual cash ISA limit will be £12,000 within the overall £20,000 ISA limit, with savers aged over 65 still able to save up to £20,000 in a cash ISA. Check the rules for the tax year you are using.
Calculate Cash ISA growth
Use the ISA calculator to estimate how your Cash ISA could grow with a starting balance, regular monthly contributions and an assumed interest rate.
ISA Calculator
Check remaining allowance and estimate future ISA value.
Types of Cash ISA access
Cash ISAs can have different access rules, so the best option depends on when you may need the money.
| Cash ISA type | How it works | Usually suits |
|---|---|---|
| Easy-access Cash ISA | You can usually withdraw money when needed, although rates may change. | Emergency savings and flexible cash goals. |
| Notice Cash ISA | You may need to give notice before withdrawing without penalty. | Money you may need, but not instantly. |
| Fixed-rate Cash ISA | You lock money away for a set term in exchange for a fixed interest rate. | Cash you do not need during the fixed term. |
| Flexible Cash ISA | You may be able to withdraw and replace money in the same tax year without reducing current-year allowance. | Savers who need more movement in and out of the account. |
When a Cash ISA may be useful
- Emergency fund: cash is normally more suitable than investments for unexpected costs.
- Short-term goals: a Cash ISA can suit money needed in the next few years.
- Tax-free interest: interest inside the ISA does not use your Personal Savings Allowance.
- Risk control: the balance does not move with stock market values.
- Simple planning: you can separate savings from day-to-day spending.
Common Cash ISA mistakes
- Ignoring access rules: fixed-rate accounts may penalise early withdrawals.
- Confusing Cash ISA with investment growth: cash interest is usually lower than long-term investment potential.
- Letting all long-term money sit in cash: inflation can reduce spending power over time.
- Withdrawing from a non-flexible ISA: replacing money may count as a new subscription.
- Forgetting transfer rules: use an ISA transfer process rather than withdrawing and paying back in.