The study, carried out by HSBC, warned that many people's retirement planning is "inadequate" and the UK is heading for an "age of the unretired".
The Future of retirement: life after work report surveyed 1,050 workers in the UK and more than 16,000 people across 15 countries. It found on average 19% of UK workers expected they would never be able to retire, against a global average of 12%.
Only 2% of UK workers who were not prepared said they would have to go back to work to cover their financial shortfall.
Instead, 44% of respondents are resigned to the idea that they will just never be able to make up their shortfall.
Heads in the sand
Head of auto-enrolment at Lorica Employee benefits Clare Abrahams told HR magazine that the research showed people still have their "heads in the sand" over how to properly prepare for retirement.
"While Government policies such as auto-enrolment are supposed to correct this, the hard truth is that until employees understand more about their future savings, the surprise factor is inevitable," said Abrahams.
"Steve Webb, pensions minister, has given himself a pat on the back re auto-enrolment, saying low employee opt-out rates are evidence of success, but a closer look shows only a tiny minority of UK pension savers are saving enough for a comfortable retirement.
"And this is not likely to be corrected even when the full auto-enrolment contribution levels come in 2018."
Among the retired, 38% found their income was less than they had expected. Of these, one-third blamed the global financial crisis, while another third said they had not planned adequately.
Generating adequate income
More than half said their outgoings since retiring were as high, or higher, than before, and they expected their savings to run out.
Around 63% of retired people worried that they did not have enough money to live on, and 70% regretted not having saved more.
Simon Williams, group head of wealth management at HSBC, said: "Generating an adequate income in retirement remains a major challenge for most people, given the financial conditions created by the global economic downturn.
"Today's workers should prepare for retirement as early as possible to have some certainty. Life is full of reasons to prioritise short-term spending over long-term planning, but the sooner people start saving, the less they are likely to need to carry on working in retirement."