More than one in five (21%) people say they have authorised payments, despite their bank or building society flagging them as suspicious.
Men are more likely to have done this (29%) than women (14%), according to a survey carried out for Nationwide Building Society.
More than a third of 16 to 24-year-olds and 37% of 25 to 34-year-olds have approved suspect payments, compared with 9% of over-55s.
However, more than a third of people have been left out of pocket by doing so.
A name-checking service called confirmation of payee is used by banks and building societies to help reduce fraud and misdirected payments.
It helps to tackle bank transfer scams, where fraudsters will try to persuade people that they are paying a legitimate organisation.
Nationwide also warned about email hack scams when making payments, after finding more than a third of people said they were not aware that criminals can intercept genuine email and text exchanges.
Ed Fisher, head of fraud policy at Nationwide Building Society, said: "It's important to be careful when receiving requests for payment over text or email as fraudsters have the capability to intercept these and make subtle changes to account details which will divert the payment to them.
"If anything in the email header looks odd, don't send the money."
The survey of more than 3,000 people across the UK in May also looked at issues with rogue traders.
It found that more than two-fifths (44%) of people have or know someone who has had work done on their property to such a poor standard that it required fixing or redoing.
While nearly a third (32%) of those got someone else to remedy the work, 12% did it themselves.
Despite poor quality work, more than a third (37%) said the money paid was not returned.
Nationwide also warned about email hack scams when making payments, after finding more than a third (35%) of people said they were not previously aware that criminals can intercept genuine email and text exchanges.
Watch: Why your bank statements might say buy-now-pay-later without you realising