The Halifax bank is increasing its upper age limit for mortgages from 75 to 80.
The mortgage lender, part of Lloyds Banking Group - the largest retail bank in the UK - announced the move in response to changing demographics.
It means that for new mortgage applications the term will be allowed to run until the borrower's 80th birthday.
Stephen Noakes, managing director for retail customer products at Halifax, said: "As demographics and working habits continue to change, we continually review our products and policies to ensure they reflect the evolving needs of our customers, including those who wish to continue working longer."
An ageing population is one of the biggest features of Britain's recent demographic change.
In the next five years, the number of consumers aged over 65 in the UK is expected to increase by 1.1 million, according to the Financial Conduct Authority.
A survey by Halifax released last week also suggested that one in three 20 to 45-year-olds expect to be working beyond their retirement age to pay off their mortgage.
Among those who are not yet on the property ladder, 39% believe they will be working later in life to pay for their property and one in 12 expect to be paying their mortgage throughout their life.
In addition, major cities are also being heralded as "unaffordable blackspots" for first-time buyers, research from Post Office Money Mortgages found, meaning it may be impossible for some younger buyers to get onto the property ladder without longer terms.
Halifax's announcement comes in the week that Barclays also announced it would offer 100% mortgages to first-time buyers.