The survey also shows that half of UK adults (25.6m people) show some financial vulnerability, meaning that they are risk of a financial crisis due to lack of protection or preparation, excessive debt or other reasons.

Financial Lives is the FCA’s largest tracking survey of consumers and their use of financial services, drawing on responses from just under 13,000 UK consumers aged 18 and over. The aim of the survey is to give the FCA  insights into people’s experiences of retail financial products and services.

The report tells the "financial story" for six different age groups to show key themes at each life stage, from those 18-24 to those 65 and over.

For all age groups, the proportions showing characteristics of vulnerability are around the national average of 50%, except that for those 75 and over the proportions showing vulnerable characteristics are higher:  69% for the 75s and over, and 77% for the 85s and over.

The highest proportion (77%) of those with these characteristics are among the unbanked, and among the unemployed who are looking for work. Women account for the larger number of those with these characteristics, compared with men (46% or 11.7 million), as 53% of UK women (or 13.9 million) are potentially vulnerable.

The data reveals:

• Just 35% of those aged 45-54 have given “a great deal of thought” as to how they will manage in retirement
• Those aged 65 and over are least likely to check if an internet site is secure before giving their bank or credit card details
• 13% of 25-34 year olds are in difficulty because they have missed paying domestic bills or meeting credit commitments in three or more of the last six months

The Financial Lives Survey 2017 results will contribute to the FCA’s understanding of financial harm in support of the FCA’s ‘Mission.’

This publication is the second in a series of documents the FCA is publishing this autumn as part of its focus on consumers. It follows the publication of our ‘Ageing Population and Financial Services’ Occasional Paper last month. The FCA will publish an overarching strategy ‘Approach to Consumers’ later this year.

The FCA will also be releasing weighted data tables with the report so that other organisations will be able to use the survey findings for research.

Andrew Bailey, FCA chief executive, said: “The findings give us a wealth of information which will be used to increase our knowledge and understanding of the issues affecting consumers and how to best protect them.

“The data gathered will be invaluable in helping the FCA prioritise our work. We also hope that the research will provide valuable insight for other organisations focusing on consumers and finance.”

Tom McPhail, head of policy at Hargreaves Lansdown, said: "Auto-enrolment has been an incredible success, helping over 8 million people so far to start building up savings for their retirement. However millions more have been left behind. Low earners, the young, part-time workers, the self-employed and people working past retirement age all risk missing out on the generous top-ups available. The sooner the benefits of this fantastic system can be extended to help more of the population, the better.’

"Neither the government not the regulator has any kind of clear policy to encourage more saving and investing; it isn’t even part of the FCA’s statutory objectives. We’d like to see this challenge given greater priority by the government as it has profound implications both for individuals and for society more generally."

• The report can be accessed here Financial Lives Survey 2017 Report