What will change inside a stocks and shares ISA when the cash ISA limit is reduced?
13 April 2026
Question by Boring Money reader
What practical changes will we see inside stocks and shares ISAs when the cash ISA limit is reduced? Will people be penalised for holding money market funds or uninvested cash — and how would that even be enforced?
Answered by Samantha Secomb
This is less about punishment and more about nudging younger savers, who have time on their side, towards investments that could work harder for them long-term. Over-65s keep the full £20,000 cash ISA allowance unchanged.
From April 2027, under 65s will see the cash ISA limit drop to £12,000, but the overall ISA limit stays at £20,000, so the remaining £8,000 must go into a Stocks & Shares ISA.
The "loophole" question is the interesting bit. HMRC has signalled it will tax interest earned on cash held inside a Stocks & Shares ISA, effectively reviving a pre 2014 rule where idle cash was taxed at 20%. It has also proposed "cash-like asset tests" that could catch money market funds.
But here's the reality: industry pushback has been fierce, with platforms warning the rules are overly complex, and recent talks suggest the plans may be softened. What counts as "cash-like" remains genuinely unresolved.
The honest answer? The government knows enforcement is messy and the detail is still being worked out in consultation. Watch this space.
