More than three quarters of adults have not set savings targets for retirement, according to Sanlam.
Research from the life insurer shows 39% of adults do not consider setting targets as being important to their financial planning.
A total of 29% of men have set a financial target for their retirement income, compared to 18% of women.
Over half (55%) of adults in the UK do not think they will be able to save enough money to retire when they want to but have not addressed the problem despite awareness of their financial circumstances.
Sanlam UK chief executive Jonathan Polin said: "The gap between what people think they need and what they actually require in later life is huge, and sometimes life-changing. Despite years of industry effort to turn the tide, engagement with longer term savings, as highlighted in our report, is shockingly low."
Those aged between 45 and 55 across both genders are considered to be most at risk, with just 18% having set retirement goals.
Polin added: "This suggests that we are about to see a tidal wave of people coming into retirement who will be ill-prepared and severely disappointed when faced with their retirement reality. By taking some very simple steps, setting clear financial goals, and identifying a clear path to get there, this nightmare can be avoided.
"It is time people are clear about their retirement number and have a clear and achievable plan to get there."
Last week, the Pensions and Lifetime Savings Association published its retirement living standards in a bid to help savers understand how much income they should aim for in order to live various lifestyles.
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