LIVEMarkets rolling coverageStarted: August 6, 2026, 4:00 AM EDTUpdated: August 6, 2026, 4:18 AM EDT UK to Introduce 22% Tax on Cash Interest in Stocks and Shares ISAs Starting April 2027 August 6, 2026, 4:18 AM EDT. Beginning 6 April 2027, HMRC will introduce a 22% tax on cash interest within Stocks and Shares ISAs, a change impacting millions of UK savers. The annual Cash ISA contribution cap will also fall from £20,000 to £12,000 for savers aged over 65. Amid these changes, investors could look to money-market funds (MMFs)-which offer increasing interest rates and present distinct risk profiles-as alternative