Britannia found that poor debt management means that “millions of Britons have no control of their finances”.
Tim Franklin, director of the building society’s member business, said: “A lot of people have a tight rein on their finances – but many spend quickly at the start of the month and leave themselves facing tough times later on.”
According to the report, most people use up their earnings 21 days into the month, putting them in debt danger until their next pay packet.
Wages are being spent by men on takeaways, gadgets and clothes, while women tend to splash out on new shoes, outfits and dinners.
Mr Franklin urged a sensible debt management plan to avoid problems, yet stressed that people can still enjoy themselves.
“With a little more planning, millions of people could get their finances under control. They could spend and save as well,” he said.