Martin Lewis warns over possible cash ISA rule change which could 'start immediately' The BBC and ITV star has issued a new video about the cash ISA tax-free allowance. Martin Lewis warns over possible cash ISA rule change which could 'start immediately' Martin Lewis has spoken out over whether the £20,000 cash ISA limit is being "killed off". The BBC and ITV star has issued a new video about the cash ISA tax-free allowance. A Cash ISA is a type of savings account that offers tax-free interest. That means you’ll be able to keep all of the interest you earn, as long as you stick to the rules of the account. Cash ISAs are available to UK residents aged 18 and over. ‌ Crown employees based overseas and their spouses are also able to open a cash ISA. 52-year-old Mr Lewis said: "They're talking about lowering the limit of how much money you could put in in future, so there's no need to panic about your existing cash ISAs if the rumours are correct. ‌ READ MORE HMRC issues warning to 'wind down' use of scheme as it begins 'crackdown' "As for when it starts, well, if it is announced in the Autumn Budget, there's a chance it could start immediately so it would instantly lower your cash ISA allowance. Or there's precedent for ISA changes for them doing the change, announcing it in autumn and starting it in the January or starting it in April 2026 – the new tax year." Article continues below He added: "For me, what all this means is if you are planning to save into a cash ISA this tax year and you've got the money, getting the money in sooner would seem safer – in case there is a risk of the allowance being cut." You open and pay into the account – this is called making a deposit. You can pay in up to £20,000 in a tax year. Interest will be paid annually or monthly, depending on the Cash ISA you pick. You won’t pay tax on the interest you earn. The interest you earn won’t count towards your personal savings allowance. In the 2025/26 tax year, you can save up to £20,000 in Cash ISA. The tax year runs from 6 April 2025 to 5 April 2026. Article continues below This can be split across different types of ISA. For example, you could save £15,000 in a Cash ISA and £5,000 in a Stocks and Shares ISA.