Mortgage brokers say it is increasingly difficult for clients over 40 to find a mortgage because of their age.
Two out of brokers say they have seen a rise of age-based rejections in the past year, Nottingham Building Society research shows.
And 34% say the over-40s will continue to face rejection despite recent lender action to ease restrictions.
Around 17% of borrowers who have been rejected say their age was a major reason for rejection, rising to 21% among those aged 45 to 54.
Both mortgage and remortgage customers are being caught out.
Around one in four of those whose age counted against them say they were not able to borrow for long enough while the rest were turned away because either they or their partner were too old.
Older borrowers are suffering as lenders need to be sure that customers have the income to afford loans even after they retire.
The Council of Mortgage Lenders and Building Societies Association are working to make it easier for older borrowers, and some lenders have increased their maximum ages.
Ian Gibbons, senior mortgage broking manager at Nottingham Mortgage Services, said: “It is baffling for people in their early 40s to be told they are too old to have a mortgage and particularly so when the average age of first-time buyers is rising which means some could even be first-time buyers.
“There is no doubt creditworthy customers are being rejected and some are facing restrictions on their choice of mortgages.
“However there are options out there for older borrowers and the key to ensuring they get the most appropriate mortgage is to search the whole market. If your existing lender is restricted on what it can do there are other options.”
The Nottingham’s research shows the main reason for being turned down for a mortgage or remortgage is a poor credit history, affecting 38%, while 19% were rejected on grounds of affordability.