Based on the answers to the poll, which assessed customers' responses to some of the common tactics used by fraudsters over the phone, via email or via text, the British Bankers' Association (BBA) has calculated how many people it believes could fall foul of the most prevalent frauds.
Worryingly, around 8 million people are thought to be vulnerable to "vishing" or voice phishing, while 4 million may transfer money into another supposed "safe" account if instructed, 3 million could be willing to carry out "test transactions" online, and 1.7 million would pass their bank card over to a courier on their doorstep if they carried some form of ID card.
To counter this, and make customers more aware of the threat, the BBA has launched a fraud awareness campaign to help people spot the difference between legitimate contact from their bank and a call from a fraudster.
A leaflet and a new website, Know Fraud, No Fraud, have advice on how to avoid becoming a victim, and what to do if you get caught out.
The leaflet also sets out eight things your bank will NEVER ask you to do:
1. Ask for your full PIN number or any online banking passwords over the phone or via email.
2. Send someone to your home to collect cash, bank cards or anything else.
3. Ask you to email or text personal or banking information.
4. Send an email with a link to a page that asks you to enter your online banking log-in details.
5. Ask you to authorise the transfer of funds to a new account or hand over cash.
6. Call to advise you to buy diamonds, land or other commodities.
7. Ask you to carry out a test transaction online.
8. Provide banking services through any mobile apps other than the bank's official apps.
"The more people know about fraud, the less likely they are to become victims," said Anthony Browne, chief executive of the BBA. "Our Know Fraud, No Fraud campaign will help you spot some of the tactics used by scammers. Your bank would never send someone to your home to collect your cash or ask you to transfer funds to a new account.
"If you suspect you have become the victim of fraud, please contact Action Fraud and your bank as soon as you can. Specially-trained staff will be able to advise on what to do next."
Information is correct as of the date of publication (shown at the top of this article). Any products featured may be withdrawn by their provider or changed at any time.