Although the average amount owed has reduced compared with the previous year, the study found that the most common reason for people getting into debt is normal living expenses.
Just 22% of the nation will not be carrying debt into 2021, according to the study by financial comparison experts money.co.uk.
A spokesman said: "What’s interesting is that 2% fewer people will be carrying over debt into the new year than this time last year.
"That means, mortgages aside, 78% will go into the New Year with some form of personal debt - including money owed on credit cards, personal loans, car loans, bank overdrafts and payday loans."
"Experts say the really concerning figure is that 35% of people’s personal debt is largely due to ‘normal’ living expenses. A further 15% say their debt is due to Christmas spending and 31% have identified that their personal debt is due to changed financial circumstances caused by the COVID-19 pandemic."
The study of British adults was commissioned by financial comparison experts money.co.uk this month and indicates that the average British adult ended 2020 with £9,246 worth of total debt – down 33% compared with last year’s average of £13,910.
Men are taking more debt into 2021 than women. UK males have an average of £11,581 debt at the end of 2020. Women have an average debt of £7,016 which they will carry over into 2021.
Salman Haqqi, personal finance expert at money.co.uk, said: “Our research shows that it has been a particularly difficult year for the country financially. There’s been the coronavirus pandemic, and with it, unemployment and furlough, plus the rising cost of everyday living to consider.
“Yet, despite this, the good news is that people are generally carrying less debt across into 2021 than they did the previous year. However, our study also shows that one in four people are paying off the minimum amount in repayments but less than the full amount on their credit card every month, which will be costing them.
"It's worrying to see that so many never move their debt around to take advantage of better interest rates, something that could save them hundreds of pounds a year and help them pay off their debts sooner.
"One of the most troubling stats is that 35% of people are using debt to pay for household essentials, showing that the cost of living just isn’t covered by their regular income.
"It's always worth going online and investigating what options are available to you, especially as the new year starts, as there may be cheaper alternatives and strong offers from lenders."