It was also found that 47 per cent of homeowners do now review their mortgage deal regularly.
Commenting on the findings, Nici Audhlam-Gardiner, Abbey's mortgage head, said: "£5 a day or £140 a month on average is not an insignificant amount of money and we know for a fact that five million people could benefit immediately by shopping around."
Research by Fool.co.uk also recently indicated that homeowners could make significant savings by shopping around for mortgage deals.
The study concluded that people could save up to £3,000 by spending more time researching their options.
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