ISA Allowance 2025/26: Using Your £20,000 Before the 5 April 2026 Deadline

As the 5 April 2026 tax year deadline approaches, many UK savers and investors are reviewing their finances and deciding how best to make use of their remaining ISA allowances and other tax-efficient allowances.

This year, the annual ISA allowance 2025/2026 remains at £20,000. This means that all UK taxpayers are entitled to shelter up to £20,000 in a Cash ISA, Stocks and Shares ISA and/or an Innovative Finance ISA (IFISA) account. If you invest £10,000 before 5 April 2026, the remaining £10,000 of your ISA Allowance 2025/2026 will disappear when the new April tax year begins.

The £20,000 ISA allowance can be kept in just one account, or across a variety of different accounts to allow for portfolio diversification. For example, stock market volatility may mean that more risk-averse investors might prefer to keep a larger sum in a Cash ISA account this year, while more risk-aware investors may wish to consider an IFISA for the first time.

ISA allowance variables for the 2025/2026 tax year

Not all ISAs follow the annual £20,000 allowance rule. There are two exceptions – the Lifetime ISA (LISA) and the Junior ISA (JISA).

Up to £4,000 can be held within a LISA, but this counts towards your overall £20,000 annual ISA allowance, so if you chose to max out your LISA this year you would have just £16,000 of your remaining ISA allowance available for other ISA accounts. The LISA is unique among other ISAs as it can only be used to buy a first home or for a pension fund. Furthermore, LISA users can only pay into the account until they are 50 years old, and pension withdrawals can’t begin until the age of 60.

Meanwhile, up to £9,000 can be added to a Junior ISA during the April-to-April tax year. This money can be invested or saved on behalf of a child, and therefore it does not impact on the £20,000 annual ISA allowance that adults are subject to. In theory, you could invest £20,000 in your own ISA accounts, plus an additional £9,000 in the account of your child, effectively meaning that you are sheltering £29,000 of your income per year from unnecessary taxation.

How to use your £20,000 ISA allowance in the 2025/26 tax year

The UK government has indicated that it is interested in reforming the ISA landscape. This has already resulted in the announcement that the Cash ISA allowance will be reduced from the current £20,000 per year to £12,000 per year from April 2027. With the prospect of change ahead, this could be a good time to ensure that you are making the most of the current ISA allowance and maximising your chances of making tax-free returns.

Before deciding how to allocate your ISA allowance, it is important that you understand the difference between the three main account options.

• Cash ISAs are viewed as lower-risk, offering variable or fixed interest rates across one, two or five years, closely tied to the Bank of England base rate. If the base rate goes down, variable rate Cash ISAs may also see their interest rates reduced.
  

   

• Stocks and Shares ISAs offer a wide range of potential returns – including the possibility of negative returns, or losses. Investors can choose from hundreds of options, including equities, bonds, and alternatives, as well as tracker funds which mirror the performance of the world’s key stock markets. A financial advisor can help you to put together an ISA-eligible stocks and shares portfolio, or you can manually select your own stocks and shares if you feel confident in your ability to read the market and understand risk.

   

• FISAs allow investors to lend money through authorised peer-to-peer lending platforms, as well as long-term asset funds (LTAFs) and open-ended property funds, while still benefiting from the tax advantages of an ISA wrapper. For investors who are comfortable with the risks associated with lending, this can offer an attractive way to generate potentially higher yields than traditional savings accounts, without experiencing the daily fluctuations associated with the stock market.

With the annual ISA allowance, the motto is ‘use it or lose it’. Even if you are not able to invest the full £20,000, any savings and investments made within the tax wrapper can help to protect your capital and returns from unnecessary taxation, while benefiting from the effects of compound interest over time – just as long as you don’t make any unplanned withdrawals. The allowance resets on 6 April, so this is the season to spring into action and come up with an ISA strategy that will carry you through the next financial year as well.