9 September 2026
A cash-stuffed mattress has appeared at London’s King’s Cross station today, bringing a major but hidden national financial issue into public view and dramatizing the hundreds of billions of pounds currently sitting idle across the UK.
As the country faces ongoing economic pressures, a dangerous wave of financial inertia has taken hold. According to the Bank of England, a staggering £303 billion in household cash is currently sitting in accounts earning zero interest. This represents a 60% increase since the onset of the pandemic of money effectively being stuffed under a mattress doing nothing1.
Quilter is taking the lead in exposing this nationwide issue, using a high-impact public stunt to highlight the hidden cost of failing to build a proper financial plan.
The installation - featuring a life-sized mattress visibly bursting with cash - serves as a striking physical metaphor for Britain’s long-standing, passive relationship with money. Built around Quilter’s core philosophy that ‘Money needs a plan’, the piece challenges passers-by and the wider public to confront whether their hard-earned money is actually working for their future. For those interested in learning more, Quilter advisers are also on-hand to help start the conversation.
To understand what is driving this national phenomenon, Quilter’s research2 uncovered a deep-seated reliance on uninvested cash:
- Deep Inertia: 27% of Britons would rather hold cash savings than invest, while 11% keep some of their savings as physical cash stored at home.
- The Advice Gap: 38% of adults do not consult anyone before making financial decisions.
- An Appetite to Learn: Crucially, 25% of people want to learn more about investing to build their confidence, but currently lack the support to do so.
- Gender divide: Men are more likely to be confident investing for the long-term compared to women (21% vs 11%) and also feel confident knowing how much to split between savings and investments (27% vs 18%).
Asked where people keep their cash at home if they do so, a safe proved to be the most popular choice (8%), followed by a secret compartment (7%) and an ornament, urn or tin (4%).
This cultural reluctance to engage with investing leaves the UK trailing significantly on the international stage. Data from the Investment Association (2026)3 reveals that almost 70% of Britons rarely or never discuss investing and according to the FCA4, 40% of people have money in current accounts that they consider as savings. As a result, UK investment participation stands at a mere 33% (Boring Money, 2026)5.
Calculations from Quilter6 shows that inflation can have a devastating impact on cash left idle. A £10,000 sum left effectively "under the mattress" since the end of 2010 would have the equivalent purchasing power of around £6,300 today, after inflation.
By contrast, the same amount invested in global equities would have grown to the equivalent of almost £25,000 in today's money, highlighting the long-term cost of failing to put spare cash to work.
By bringing this national blind spot out from under the mattress and into one of the UK's busiest transit hubs, Quilter is driving an essential national conversation - challenging Britons to break free from passive cash reliance and give their money a long-term plan. The activation also supports the wider ambitions of Invest for the Future, the industry-backed campaign working to improve confidence in investing.
Jo Harris, Chief Customer and Operations Officer at Quilter, said: “Cash savings have long played an oversized role in the financial psyche of consumers in this country. The tide is beginning to turn, and people are recognising the crucial role investing can play in growing their money, but more still needs to be done.
“Cash, of course, plays an important role in our personal finances, but we wanted to bring the problem of excessive cash savings to life. The familiar image of cash being stuffed under a mattress for the future is not a suitable financial strategy, yet many consumers do just that by leaving money in low or no-interest savings accounts.
“The data shows that people want to learn about investing but lack the confidence to take the first step. We hope this installation helps people recognise that their money needs a plan and that they do not need to go it alone.”
Data sources
1. Bank of England Database, June 2026: Monthly amounts outstanding of monetary financial institutions' sterling non-interest bearing deposits (inc. transit and suspense) from household sector (in sterling millions) not seasonally adjusted.
2. Quilter commissioned YouGov UK Survey, July 2026: Responses from 2,047 adult respondents across the UK analysed, in relation to statements around their approach to savings, investing and where money is kept.
3. The Investment Association, April 2026: 69% of people saying they rarely or never talk about it (investing).
4. Financial Conduct Authority: Financial Lives Survey, 2024: 40% Have money in current accounts considered to be savings.
5. Boring Money’s The future of advice report, 2026: The proportion of UK adults investing, defined as holding a Stocks & Shares ISA, a personal pension or a GIA, stands at 33% in 2026
6. Quilter, September 2026: Calculations of impact of inflation and investment returns on £10,000, using Consumer Prices Index (CPI) and IA Global Equity returns from December 2010 to July 2026.
