The amount of money Britons owe broke through the £1 trillion barrier for the first time during June, according to the Bank of England.
The money is owed through a combination of mortgages, personal loans, overdrafts, hire purchase agreements and on credit and store cards.
About 80% of the £1.004 trillion is in the form of loans secured against dwellings, such as mortgages and re-mortgages, the bank said.
The amount people borrow has been booming in recent years due to feel-good factors such as soaring house prices and low unemployment combined with low interest rates making it cheap to borrow money.
British household debt is now equal to the total amount owed by Africa, Asia and Latin America to international banks and through loans from other countries.
But consumer groups and MPs have warned that people could be storing up problems for the future, with rising interest rates making debts unmanageable.
The National Consumer Council said around six million families were already struggling to keep up with credit repayments, and hikes in the cost of borrowing could lead to more people facing problems.
Citizens Advice said it had seen a 44% increase in the number of people coming to it for help with debt in the past six years.
But despite the increasing concern, for the time being mortgage repossessions continue to fall, the Council of Mortgage Lenders said this week – see our story today Repossessions still falling, but for how long?