Question to the HM Treasury:

To ask the Chancellor of the Exchequer, what representations she has received from the investment management industry on changes regarding money market funds in stocks and shares ISAs.

At Autumn Budget 2025, the Government announced a reduction in the Cash ISA limit for those under 65, to encourage retail investment and drive better returns for savers. Rules are needed to protect the integrity of the Government’s objectives and ensure that the lower cash limit is respected.

HMRC does not currently collect data from ISA managers on investment in money market funds (MMFs) or the purpose for which they are held. MMFs are advertised by the finance industry as low risk alternatives to cash, but they are also used as temporary holding vehicles.

The new rules will not prevent investment in MMFs but ensure MMFs do not constitute the sole investment held in a stocks and shares ISA. Further details of the rules are contained in the HMRC factsheet published at Tax Update 2026 at Tax Update 2026- www.gov.uk/government/publications/fiscal-events-2026-factsheets/isa-reform-2027-anti-circumvention-rules-factsheet

The new rules are the product of extensive engagement with managers of cash and stocks and shares ISAs, alongside trade bodies and savings infrastructure suppliers. The resulting rules are as simple as possible for providers and consumers and retain maximum flexibility for consumers to build an investment portfolio that works for them.