A Cash ISA (Individual Savings Account) is a UK savings account. With this account you can earn interest on your money without paying tax on it. Each tax year, there is a limit on how much you can contribute across all types of ISAs, including Cash ISAs.
For the 2026/2027 tax year, the total ISA allowance is £20,000. This means you can only save or invest up to this amount in ISAs combined within the year, whether you choose to place all of it in a Cash ISA or split it between different ISA types. Let’s see how it works.
| What is a Cash ISA account? | A UK savings account where interest earned is tax-free |
| What is the Cash ISA allowance? | The total amount you can put into ISAs each tax year without paying tax |
| What is the limit for 2026/2027 tax year? | £20,000 total ISA allowance |
| What is the limit for 2027/2028 tax year? | Probably £12,000 on Cash ISA allowance |
How Does the Cash ISA Allowance Work?
Your cash ISA allowance is simply the portion of your overall £20,000 that you choose to put into a cash ISA. You can decide how much of your total ISA allowance goes into cash, and how much goes into other ISA types.
Remember, you cannot exceed the total ISA allowance across all your ISAs in the 2026/2027 tax year. Even if you open multiple cash ISAs, the combined amount you deposit into them cannot surpass your overall allowance. However, you may prefer to keep things simple by opening just one cash ISA each tax year.
You should know that a Cash ISA (Individual Savings Account) is a type of savings account that allows you to earn interest on your savings without paying tax on that interest. Unlike a standard savings account, any interest you earn within a Cash ISA is completely tax-free, making it an efficient way to grow your savings over time.
Cash ISAs are designed for low-risk saving, meaning your money is typically protected and grows through interest rather than investment returns. You can usually access your funds easily, depending on the specific account terms, making them suitable for both short-term and long-term savings goals.
| ISA Type | 2026/2027 Maximum Subscription | Age Requirement | Key Features |
| Cash ISA | Up to £20,000 | 18+ (to open) | Tax-free interest, flexible withdrawals, fixed and variable-rate products available. |
| Stocks and Shares ISA | Up to £20,000 | 18+ | Potentially higher returns, but comes with investment risk. Dividends and capital gains within the ISA are tax-free. |
| Innovative Finance ISA | Up to £20,000 | 18+ | Peer-to-peer lending and crowdfunding investments; generally higher rates but higher risk. |
| Lifetime ISA (LISA) | Up to £4,000 (within £20,000 total) | 18–39 (to open) | Government bonus of 25% on contributions. Designed for first-home purchase or retirement. Withdrawal rules apply. |
| Junior ISA (JISA) | £9,000 (separate from adult ISA) | Under 18 | Parents/guardians can open for a child. Funds are locked in until the child turns 18. |
Cash ISA Allowance update for 2027
The UK government is expected to change the ISA rules starting in the 2027/2028 tax year. Under the new system, the Cash ISA allowance may be reduced from £20,000 to £12,000 per year for most savers. This means people under the age of 65 will only be able to save up to £12,000 in a Cash ISA each year while still receiving tax-free interest.
The remaining ISA allowance (up to the total £20,000 limit) is expected to be used for investments, such as Stocks and Shares ISAs or other eligible ISA types.
The aim of this change is to encourage more people to invest rather than keep large amounts of money in cash savings. But remember that Cash ISAs will still exist and will remain tax-free. These changes are still expected and may be confirmed or adjusted before they come into force.
The Government is introducing also a 22% tax charge on any interest earned on cash held within non-Cash ISAs (for example Stock and Shares ISA) to discourage long-term cash holdings.
What happens if you exceed the ISA allowance?
If you put more money into ISAs than your annual allowance, the excess amount is not allowed. In most cases, your ISA provider will contact you and ask you to remove the extra contributions. If the money is not corrected, HMRC may remove the tax-free status from the excess amount.
This means you could lose the tax benefits on the extra savings, so it is important to track your contributions carefully across all your ISAs.
An example of how you can split your £20,000 ISA allowance.
| ISA Type | Amount Invested |
| Cash ISA | £8,000 |
| Stocks & Shares ISA | £7,000 |
| Lifetime ISA | £2,000 |
| Innovative Finance ISA | £3,000 |
| Total | £20,000 |
How does transferring an ISA affect your allowance?
You can transfer your ISA from one provider to another at any time, and you will not lose the tax-free benefits on your savings. This means your money will continue to grow without being subject to tax, even after the transfer is completed.
It is also important to know that the transfer process does not affect the status of your existing savings, as long as it is done correctly through an official ISA transfer.
When you transfer an ISA, any money you have contributed in previous tax years will not use up your current year’s ISA allowance. This means only new money paid in during the current tax year counts towards your annual limit.
As a result, transferring your ISA does not reduce the amount you are allowed to save in the current tax year, and your full allowance remains available for new contributions. You can transfer your ISA to Moneyfarm in a simple and free way, to save and invest, and leave the rest to us.
Keeping your tax-free benefits
Make sure you follow the official transfer process—this usually involves completing a transfer form through the new provider. If you withdraw the money yourself instead, you’ll lose the tax-free status on those funds. By letting your provider handle the transfer from start to finish, you can seamlessly switch ISAs while preserving your annual allowance.
Keeping your tax-free benefits
Make sure you follow the official transfer process—this usually involves completing a transfer form through the new provider. If you withdraw the money yourself instead, you’ll lose the tax-free status on those funds. By letting your provider handle the transfer from start to finish, you can seamlessly switch ISAs while preserving your annual allowance.
Who can open a Cash ISA?
Cash ISAs are designed for UK savers who want to earn tax-free interest on their money in a simple and low-risk way. To open a Cash ISA in the UK, you must meet a few basic requirements
- You must be at least 18 years old
- You must be a UK resident for tax purposes
- You must have a National Insurance number
Can you withdraw money from a Cash ISA?
You can withdraw money from a Cash ISA, but it depends on the type of account you have. Some Cash ISAs are flexible, which means you can take money out and put it back in during the same tax year without affecting your allowance.
Other ISAs may have restrictions, especially fixed-rate accounts, where withdrawals could reduce your interest or come with penalties. It is always important to check the terms of your specific ISA before making a withdrawal.
Here are the differences between withdrawing and transferring a Cash ISA.
| Feature | Withdrawing money | Transferring an ISA |
| Process | You take money out of your ISA into your bank account | Your ISA is moved directly from one provider to another |
| Tax benefits | You may lose ISA tax benefits on withdrawn money if not re-deposited correctly | You keep all tax-free benefits |
| ISA allowance impact | Money withdrawn may use up your current year allowance | Does not affect your annual ISA allowance |
| Flexibility | High flexibility, but less tax protection | Fully controlled process with tax protection |
| Risk of error | Higher risk if you re-deposit incorrectly | Low risk if done through official transfer process |
| Best for | Short-term cash needs | Changing provider or getting better rates without losing benefits |
Common mistakes with Allowance and Cash ISAs
Many people make simple mistakes when using Cash ISAs, such as
- Forgetting that the ISA allowance is shared across all ISA types
- Not tracking total contributions
- Withdrawing money from a non-flexible ISA and assuming it can be replaced without affecting the annual allowance
- Assuming the allowance resets every month instead of every tax year
- Not checking interest rates or ISA type before choosing an account
Avoiding these mistakes can help you make better use of your tax-free savings allowance. Remember that when you decide to save money or invest it in any way, your choices should always be based on a careful analysis of your goals, the level of risk you are willing to take, and the time horizon you have available. If you want to make the best choice, you can rely on experts, such as the advisors at Moneyfarm.
Frequently Asked Questions
No. Any interest or investment gains you earn within an ISA do not count against your annual ISA allowance. The allowance refers only to the amount you deposit or invest in the ISA within a single tax year.
If you accidentally pay in more than the annual limit, your ISA provider may return the excess funds or freeze the additional deposit. You should also notify HMRC, as you may need to withdraw or reclassify the surplus amount to avoid potential tax implications.
Your ISA allowance resets at the beginning of each tax year, which runs from 6 April to 5 April the following year. Any unused allowance from the previous tax year does not roll over to the next.
No, contributions to a Junior ISA do not reduce your personal ISA allowance.
.A Junior ISA has its own annual allowance of £9,000 per tax year in 2026.
No. ISAs are solely for individual UK residents. A limited company cannot open or hold an ISA. If you require a savings account for your business, you’ll need to look into alternative business banking or investment products.
No, you do not pay tax when you withdraw money from an ISA. All withdrawals are tax-free because the money has already been protected.
Yes, you can open a new ISA each tax year if you want. Many people choose to open a new ISA to take advantage of better interest rates or different account features.
Yes, you can have multiple ISAs at the same time, but your total contributions across all ISAs must not go over your annual allowance.
*As with all investing, financial instruments involve inherent risks, including loss of capital, market fluctuations and liquidity risk. Past performance is no guarantee of future results. It is important to consider your risk tolerance and investment objectives before proceeding.
