The figure rises to four in ten when looking at working-age households, the report found.
Almost three quarters of low-income households north of the border who are in receipt of Universal Credit are meanwhile in some form of household arrears.
Almost a quarter of low-income households in Scotland have taken on new borrowing, or increased the amount of borrowing they have during the pandemic.
The analysis looks at households in the bottom 40 per cent of incomes in the UK – those with a household income of £24,752 or less. This represents around 11.6 million households across Britain.
In total UK-wide, 3.8 million low-income households are in arrears, with bills totalling £5.2 billion. The report also concluded that 950,000 were in rent arrears; 1.4m are behind on council tax bills; and 1.4m are behind on their electricity and gas bills.
A large majority of households who are now behind on their household bills said they were always or often able to pay all their bills in full and on time before the pandemic hit.
Families with children, households with a person under 45 answering the survey and ethnic minority households were all more likely to say they had fallen into arrears with bills.
Of the households surveyed who receive Universal Credit, 40 per cent are not confident they will be able to pay their bills in full on time, while 35 per cent do not think they will be able to avoid taking on more debt.
Half of these households say they do not feel confident they can find a job or work more hours.
The UK Government has cut the £20 uplift to Universal Credit that was brought in during the pandemic.
Katie Schmuecker, deputy director for policy and partnerships at JRF, said households were in a “debt crisis”.
She said: “Behind these figures are parents gripped by anxiety, wondering how they will put food on their children’s plates and pay the gas bill, [and] young people forced to rely on friends to help cover their rent and avoid eviction.
“While many households on higher incomes have enjoyed increased savings and rising house prices during the pandemic, people on low incomes are under serious financial pressure that shows no sign of abating.
"As a society, we believe in protecting one another from harm. As costs pile up and incomes have been cut, we urgently need to rethink the support in place for people at the sharp end of the cost of living crisis.”
She added: “We know the Chancellor is capable of taking bold action to protect people from harm when it is required. Reinstating the £20 per week increase to Universal Credit and boosting funding for councils to tackle debt must be priorities in next week’s Budget.”
SNP work and pensions spokesperson David Linden MP said: “This latest report from the Joseph Rowntree Foundation lays bare the consequences of cutting Universal Credit, hiking taxes and imposing a hard Brexit on the UK during a pandemic.
"Each of these decisions have hit the lowest earners in our society the hardest – something we have sadly become accustomed to under this Tory government."