Many people may be over-confident about their ability to spot a scam, research suggests.
Four-fifths (80%) of over 2,300 people surveyed for the Take Five to Stop Fraud campaign say they could confidently identify a fraudulent approach.
But in a separate test of over 63,000 people, less than one in 10 (9%) scored full marks in the Take Five Too Smart To Be Scammed? quiz.
The quiz presents people with texts and emails and asks them to say whether they think they are from a genuine organisation or fraudulent.
One text, purporting to be from a bank, asks the recipient to transfer money to a "safe" account - something which banks would never ask their customers to do.
In another scenario, an email asks the recipient to click on a link - something which consumers are also warned by the campaign not to automatically do.
The email contains grammatical errors - another warning sign that it is fraudulent.
Take Five to Stop Fraud Week, which runs from January 22 to 26, is urging people to remember the mantra: My money? My info? I don’t think so!
Figures from trade association UK Finance show £366.4m (€416m) was lost to financial fraud in the first half of 2017 - with a further £101.2m (€115m) lost through authorised bank transfer scams.
Katy Worobec, managing director of economic crime at UK Finance, said: "Criminals are using very sophisticated methods, so it’s more important than ever that people are aware of how to protect themselves from fraud.
"During Take Five to Stop Fraud Week we want to spread the message that you should always question any calls, texts or emails asking for your details out of the blue.
"Stop and think before you give away any information, no matter how legitimate the person sounds - and remember - it’s My Money? My Info? I don’t think so.
"If you are unsure, then hang up and don’t reply and contact the organisation directly on a number you trust."
A genuine bank or organisation will never contact you out of the blue to ask for your Pin, full password or to move money to another account.
Only give out your personal or financial details to use a service that you have given your consent to, that you trust and that you are expecting to be contacted by.
Never automatically click on a link in an unexpected email or text.
If you’re approached with a request for personal information, do not provide it. Instead, contact the company directly using a known email or phone number.