Isa providers say new tax charge makes key investment product overly complex

By the Editorial Team · Wednesday, June 24, 2026

HM Revenue & Customs will impose a 22 percent tax on interest earned from cash held within stocks-and-shares ISAs starting in April and restrict investments in cash-like assets to encourage more equity investments. This change aims to promote UK capital markets but has raised concerns among ISA providers about increased complexity and reduced tax efficiency for investors.

HM Revenue & Customs (HMRC) has announced that interest earned on cash held within stocks-and-shares Individual Savings Accounts (Isas) will be subject to a 22 percent tax starting in April. The move is part of the government’s broader strategy to encourage savers to invest more in UK-listed equities and support the domestic capital markets.

Under the new regulations, stocks-and-shares Isas will no longer be permitted to be invested entirely in "cash-like assets," including money market funds, according to HMRC. These funds, which invest in short-term bonds and are commonly used as a low-risk entry point for investors, will face restrictions aimed at preventing savers from circumventing new limits on cash holdings within Isa accounts.

The government’s latest measures come in the wake of changes introduced during last November’s Budget, which introduced a cap of £12,000 on the annual cash allowance for under-65s, down from £20,000. By limiting the ability to hold large amounts of cash inside investment Isas, officials hope to discourage an overreliance on cash holdings within these tax-advantaged products and instead promote longer-term equity investments.

Isa providers have expressed significant concerns about the implications of the new rules. Brian Byrnes, director of personal finance at Moneybox, characterised the alterations as introducing “new charges, restrictions and eligibility rules” that threaten to complicate the investment process and reduce the attractiveness of stocks-and-shares Isas, which have long been a key component of UK savers’ portfolios.

Similarly, Alex Campbell, director of external affairs at investment platform Freetrade, described the tax charge as potentially undermining the tax efficiency of these accounts. He cautioned against possible unintended consequences, warning that the new regime might inhibit platforms’ ability to market stocks-and-shares Isas as advantageous tax wrappers for investors.

The government maintains that the adjustments are designed to channel more savings into capital markets, aiming to improve long-term financial outcomes for individuals while sustaining growth in the UK economy. However, some financial services providers argue that the changes risk adding complexity and may deter some investors.

Separately, the Treasury has launched a consultation on introducing a First Time Buyer Isa, intended to help prospective property purchasers build deposits regardless of age. Full details of this initiative are expected to be unveiled in an upcoming Budget statement.

HMRC and the Treasury have not provided further comment on the new Isa rules following requests for clarification.

This article was reported by synthesizing coverage from multiple independent news outlets to present a balanced, unbiased account. Read about our editorial standards. Spotted an error? Let us know.