An estimated 14 million people across Britain suffered an income shock in the last year, according to StepChange Debt Charity.
Research for the charity among more than 4,000 people found that nearly one in three (28%) had suffered an unexpected fall in their income in the past year - equating to 14 million people if the findings were projected across Britain.
Nearly one in 10 (9%) people surveyed had faced two or more income shocks in the past year.
StepChange also found that despite the economic recovery, 9.4% of families with children - equating to 750,000 across Britain - are in severe problem debt.
It estimates that 2.6 million adult Britons are struggling with severe problem debt, amounting to around one in 20 (5.2%), according to the survey.
The charity warned that the changing nature of working life has created a "new normal", where unexpected falls in income will become a regular feature of many people's lives.
It said that people who were not in a "secure" form of work, such as working a zero hours contract, faced a higher threat of an income shock.
Many people who experienced income shocks ended up with problem debts.
The report found that 7% of people who experienced one shock in the last year ended up in severe problem debt, as did 22% of those who experienced two or more income shocks.
People were defined as being in severe problem debt if they showed three or more signs of financial difficulty.
Signs of financial difficulty included only making minimum debt repayments for three months or more, falling behind on essential bills, using credit to pay essential bills, taking out new loans to meet repayments for existing ones, using credit to make it through to payday and regularly being hit with overdraft or late repayment charges.
StepChange said that to reflect income shocks being a fact of life, people need more help to build up their precautionary "rainy day" savings.
Mike O'Connor, chief executive of StepChange, said: "People have always faced ups and down in their incomes, but the changing nature of work means that income shocks are now a regular feature of more people's lives.
"These changes may be here to stay and social policies need to reflect the new normal. Our social policy is not keeping up with our economic policy."