An estimated 6.5 million Britons have been forced to rely on credit in the past 12 months after their income unexpectedly took a turn for the worse, according to debt charity StepChange.
The charity is warning that many people are at serious risk of debt problems by using credit as a safety net to plug surprise gaps in their income.
It is calling for better support to ensure that temporary income shocks do not become more severe, including encouraging people to build up a savings safety net of £1,000 - which it estimates could prevent 500,000 families from falling into problem debt.
The charity also wants people who are struggling with debt to be given more "breathing space", with a halt being put on enforcement action.
A survey of nearly 5,000 people for StepChange found that 8% of people had used credit to cope with a shock change in their circumstances over the last year - equating to four million people if the findings are projected across Britain.
A further 5% said they had relied on a combination of credit and benefits to get them through an unexpected change - equating to 2.5 million adults across the population.
Taken together, this would mean that around 6.5 million Britons have relied on credit in the last year to get them through a surprise change in circumstances.
Nearly one in three (28%) people across the survey said they had experienced some surprise change in their income in the last 12 months - equating to 14 million Britons.
Mike O'Connor, chief executive of StepChange Debt Charity, said: "We all face life's ups and downs, but for too many the result is severe problem debt - which can affect their work, relationships and even their mental health.
"With so many people at risk, we must take action to improve safety nets and ensure they are there for people the moment problems strike.
"This does not mean more welfare benefits, but instead we need to support people in saving to protect themselves against income shocks and give them breathing space to recover when they fall into difficulty."
StepChange's own research among its clients who have been struggling with debt found that 43% said it led to them being unable to concentrate at work and 61% felt less confident about getting a promotion.