The number of tenancies signed by a single tenant has fallen, according to the latest HomeLet Rental Index.
Last year, tenants living on their own accounted for just 33% of new tenancies, down from 67% in 2008.
The number of new tenancies signed by two tenants jumped from 28% to 52% in the same period.
According to HomeLet's figures, the number of new tenancies signed by three or more tenants increased from 5% to 15% between 2008 and 2015.
The landlord insurance provider suggests that its figures may well reflect a trend of more families moving into the Private Rented Sector (PRS).
It points to the latest English Housing Survey, released last month, which reported that the number of privately rented homes let to families with dependent children has risen from 30% to 37% over the past 10 years.
The index also reports that the average rental agreement signed in the UK outside of London was 4.8% higher in the three months to February 2016 when compared with the same time last year.
This figure represents a fall when compared with last month's index, which reported that the average rent in the three months to January was 5.5% higher than the previous year.
HomeLet says the average rent in the UK – excluding the capital – is now £744 per month.
The average monthly rent in London, meanwhile, is now £1,521.
Average monthly rents increased in 10 of 12 UK regions in the three months to February. Only in the North West and the North East are average rents now lower than they were this time last year.
“Average rents are still rising and while we are not seeing the double-digit increases recorded in some areas of the country during the summer of last year, the cost of a new tenancy continues to rise more quickly than general inflation,” says Martin Totty, chief executive of Barbon Insurance Group – HomeLet's parent company.
“Landlords are letting out homes to many more families, with rental property representing an increasingly important alternative to owner occupation; we’re also seeing people manage with higher rents by meeting the costs as joint tenants.”