Nearly half of people are worried about money despite the economic recovery - and a "sizeable minority" spend beyond their means every month - a report has found.
Some 47.5% of people surveyed for a report by Isa provider Scottish Friendly and think-tank the Social Market Foundation said they are worried about money.
The report also found that households in London have less cash left over each month, when housing costs such as rent or mortgages are taken into account, than those in most other UK regions, with the exception of north-east England.
Young people and the self-employed were also particularly likely to be tipped into the red by essential costs.
One in five (20%) 18- to 24-year-olds were spending more than their income each month on housing and related costs alone - while nearly one in three (28.5%) people in this age group went into the red after other essential outgoings such as transport costs, groceries and phone and internet subscriptions were taken into account, the report found.
Those who were more well-established in their careers were also struggling to balance their finances. Nearly a quarter (22.4%) of 25- to 34-year-olds were not earning enough to cover the cost of their housing and other essentials, the report found.
And more than a quarter (25.9%) of those in self-employment also said they were in the red after paying for housing and other essentials each month. Among those working full-time, 13% were also spending more than they were earning.
The survey asked 2,000 people about their income and their outgoings.
It found that the average UK household had £1,264 left to spend each month after paying for the essentials of housing, energy and water.
But when other outgoings such as groceries, transport, childcare and broadband were taken into account, the average household had just £905 left over each month to pay for other goods such as clothing and furniture as well as putting money into savings and saving towards holidays.
People aged between 18 and 24 years old had just £532 a month left over after housing costs and other essential spending, while those aged 55-plus - many of whom will have cleared their mortgage - had £1,198 left over to spend.
In London, households have £1,191 left over on average per month on average when housing costs alone are taken into account, compared with averages of £1,334 in Scotland and Yorkshire, £1,245 in Northern Ireland and £1,314 in Wales.
The report said that despite people in London tending to have higher wages, the lower amounts of income that households there have left over reflects the higher cost of housing in London and the South East swallowing up bigger chunks of people's incomes.
Half (50.3%) of people across the survey worried about how they would cope with a big, unexpected bill and more than one in three (35.5%) were worried about debts.
While four in 10 (41%) people surveyed expect to be financially better off in 12 months' time, 24% think they will be worse off, and the remaining 35% are unsure whether their financial situation will improve or not.
Calum Bennie, a savings expert at Scottish Friendly, said: "Headline economic data suggests that the financial situation of UK households should be improving.
"Subdued inflation, high employment and gradual increases in wages theoretically help consumers feel better off. However, any of these benefits seem to be offset by the rising cost of living and housing costs in particular.
"These day-to-day financial pressures are leaving people worried about their disposable income and a sizeable minority actually find themselves spending beyond their means every month."