A report by Bristol University and the International Longevity Centre (ILC-UK) found that about two-fifths (40%) of people aged 75 and over and who still have a mortgage to pay off have an interest-only mortgage with no linked investment with which to pay back their loan. This figure dropped to just 6% for people aged 50 to 54 who still have a mortgage.
Interest-only mortgages, which allow borrowers to pay off the capital only when the mortgage term ends, have become much less available since the boom years amid concerns about people not being able to pay back their debt.
Earlier this year, the Financial Conduct Authority found home owners have been failing to put enough money aside on up to half of the 2.6 million interest-only mortgages due for repayment over the next 30 years.
Mortgage lenders recently agreed to alert at-risk customers to help them avoid "payment shocks".
The Bristol University/ILC-UK research found nearly one in 10 (9%) households headed by someone aged in their late 60s still had a mortgage to pay off.
Peter Tutton, head of policy at StepChange Debt Charity, said: "It is essential that lenders show forbearance and work with customers to establish suitable options to prevent people from losing their homes in retirement."