Excluding mortgages, average debt per household rose sharply in 2018 to a new peak of £15,385, up £886 in a year, the research says.
The TUC says government austerity and years of wage stagnation are to blame.
But the TUC’s figures include student loans, while Bank of England figures, excluding student loans, give a debt total of half the TUC’s estimate.
The Bank of England says growth in consumer credit has been gradually slowing since the end of 2016.
The TUC arrived at its figure for unsecured debt by adding up the total amount owed in bank overdrafts, personal loans, store cards, payday loans and outstanding credit card debts, as well as student loans.
Reliant on borrowing
Unsecured debt as a share of household income had now reached 30.4%, the highest it had ever been, the TUC said.
It added that millions of households were now reliant on borrowing to get by, with working families on average worse off than before the financial crisis.
TUC general secretary Frances O’Grady said: “Household debt is at crisis level. Years of austerity and wage stagnation has pushed millions of families deep into the red.
She said the government was “skating on thin ice by relying on household debt to drive growth”, adding: “Our economy is not working for workers. They need stronger rights and bargaining powers.”
The TUC also called for an increase in minimum wage levels to £10 an hour “as quickly as possible”. The National Living Wage for workers aged 25 and over is currently £7.83 an hour and is due to rise to £8.21 in April.