Cash millionaires expose UK’s investment culture gap

Britain’s savers are sitting on a mountain of idle cash. New analysis from Bowmore Financial Planning, based on HMRC data, shows 33,700 people declared enough interest income last year to imply bank or building society balances of at least £1m each.

The figure underlines how many affluent households continue to prioritise capital preservation over growth, even as the government tries to nudge money into productive assets.

The numbers are striking. For someone to generate the interest thresholds that flag these accounts while earning less than £1m in deposits, they would need sustained rates above 5 per cent. In reality, best-buy fixed-rate ISAs hovered around 4.8 per cent and the average one-year fixed ISA rate in 2024-25 was just 4.29 per cent.

Most of these balances are therefore larger still – probably north of £1.1m. Cash has its uses for liquidity and short-term security. Holding multi-million-pound sums in it for years does not.

Equities’ long-term edge over cash remains decisive

Over the decade to the end of May 2026, global equities delivered average annual returns of 12.9 per cent, according to the MSCI World index. UK government bonds, measured by the MSCI UK government bond index, returned a negative 0.98 per cent a year. One-year fixed-rate cash ISAs managed just 2.18 per cent. The gap is not subtle. Inflation compounds the problem: cash that fails to keep pace steadily erodes purchasing power.

Mark Incledon, chief executive of Bowmore Wealth Group, puts it bluntly: “The sharp rise in the number of people holding seven-figure sums in cash suggests many investors are prioritising safety over long-term growth. While that can feel comfortable, it comes with a hidden cost: negative real returns after inflation.”

He adds that remaining on the sidelines with large cash balances is itself a significant investment decision, one that many savers appear not to have fully weighed.

Volatility fears keep many on the sidelines. Short-term market swings dominate the news cycle and the personal psyche. Yet investors with genuine multi-year horizons can mitigate risk through diversification and disciplined rebalancing. Professional advice can help match portfolios to individual goals and risk tolerance. The alternative – permanent residence in low-yielding deposits – carries its own, quieter risk.

Policymakers still struggle to shift the savings culture

The persistence of these cash piles also highlights the limits of official efforts to encourage investment. HM Treasury has made clear its desire to move more household savings out of cash and into UK equities and infrastructure, arguing that doing so would support growth and improve personal financial resilience.

The Leeds Reforms and related initiatives form part of that push. Yet the continued accumulation of seven-figure cash balances suggests the message has not fully landed.

Incledon is direct on the point: “The UK has a strong savings culture, but we also need a strong investment culture. Too much wealth is sitting in low-yielding accounts when it could be working harder for individuals and supporting growth in the wider economy.”

Cash will always have a role. Emergency funds, near-term spending needs and genuine risk aversion all justify holding some money in deposits. The issue is scale. When tens of thousands of households park more than a million pounds each in accounts that historically lag inflation and equities by a wide margin, the opportunity cost becomes systemic.

For individuals it means slower wealth accumulation. For the economy it means capital that could finance businesses and infrastructure instead sits inert.

Convincing cautious savers to cross the threshold from cash to markets remains unfinished business for the chancellor. The data suggest that comfort still trumps compounding for a sizeable and affluent cohort. Until that changes, Britain’s investment culture will lag its savings culture, at a measurable cost.

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