The financial concerns of staff are impacting on the UK's overall productivity, according to the Social Market Foundation.
The think tank's 'Working Well' study found that one in eight workers (13%) report that money worries have affected their ability to concentrate at work - equivalent to more than three million workers.
Four in ten workers (40%) said money worries have made them feel stressed over the last year, while more than a quarter (27%) said they were at a "tipping point" financially.
A quarter (25%) said they have lost sleep over money worries, and nearly half (48%) are not putting any money aside for anything more than regular bills.
Kate Evans, economist at the Social Market Foundation, said: "The UK's workforce lacks financial resilience. It's clearly affecting our ability to concentrate at work and blunting our productivity.
"The low financial resilience is a problem across industries - and it's getting worse. The proportion of workers reporting that they face financial difficulties nearly doubled over the decade to 2013/14.
"These money worries have a clear impact on how people feel and behave as they go about their day-to-day lives and jobs."
Monica Kalia, co-founder of employee benefits provider, Neyber, which worked on the research with the Social Market Foundation, said: "These findings should provide a wakeup call for UK employers, because they clearly demonstrate how productivity is impact by factors such as stress and anxiety, with both driven by financial worries. The face that these issues are apparent across all sectors of the economy means that we have consistently failed to recognise some of the key drivers of poor productivity in the UK economy.
"For far too long, politicians, policy makers and economists have chided Britain's workforce for its failure to improve productivity without taking account of the wellbeing factors that can affect employees. This clearly has to change if we are to continue to emerge from the recession with a workforce that is fit to deliver economic growth at home and meet the competitive challenge in global markets."