These new guidelines only apply to new contributions and transfers made from 6 April 2027 onwards; any funds already held in existing Cash ISAs remain tax-sheltered.
Starting 6 April 2027, the Cash ISA limit for savers aged 64 and under will drop to £12,000. While the overall annual ISA allowance remains at £20,000, any contributions above £12,000 must be directed into other ISA types, such as a Stocks & Shares ISA.
The new rules, confirmed by HM Revenue and Customs (HMRC), feature specific limits, exemptions, and anti-circumvention legislation:
Age Exemptions For savers aged 65 and over (and throughout the entire tax year in which you turn 65), the Cash ISA limit remains at £20,000.
Overall Allowance The total maximum amount you can contribute across all types of ISAs remains capped at £20,000 per year.
Transfer Bans To stop savers from getting around the new limit, individuals under 65 will be banned from transferring funds out of a Stocks & Shares or Innovative Finance ISA into a Cash ISA.
Stocks & Shares ISA Cash Limit To prevent people from stashing large amounts of cash in an investment ISA, HMRC will introduce a 22% tax charge on any interest paid on uninvested cash within a Stocks & Shares ISA.
Money Market Funds You will still be allowed to hold certain low-risk Money Market Funds in a Stocks & Shares ISA, but they will not be allowed to make up 100% of your portfolio.