TSB is warning consumers to remain wary of scams on social media platforms including Facebook, WhatsApp and Instagram.
The bank claims fraud that comes through these Meta companies made up around 80% of cases within its own three biggest scam categories.
This includes purchase, impersonation and investment fraud.
TSB found 80% of purchase fraud cases at TSB involved scams that took place through Meta platforms - with three fifths (60%) of these cases coming from Facebook Marketplace, followed by Instagram (18%).
Scam activity on Meta platforms led to 86% of impersonation fraud cases over the year – driven by a sharp increase in WhatsApp-based Friends and Family Fraud.
Alarmingly, the data shows cases coming through the WhatsApp platform increased by 300% in a year.
Scams taking place through Meta account for almost nine in 10 (87%) of all investment fraud cases at TSB.
TSB looked at customer fraud data from January 2021 to December 2022 to come up with its findings.
Its own fraud experts are now urging people to watch out for unsolicited messages claiming to be from family, or close friends.
You should always speak to the person directly, if possible, before ever sending a payment.
TSB launched its own fraud refund guarantee in 2019 and it said 97% of fraud cases it sees are reimbursed through this.
The guarantee covers customers who are innocent victims of fraud on their TSB account.
Paul Davis, director of fraud prevention, TSB, said: "Social media companies must urgently clean up their platforms to protect the countless innocent people who use their services every day.
"In the meantime, we are urging the public to remain cautious to potential scam content - and to spread the word to help protect those around you.
"It's high time that social media and telephone companies took financial liability for the rising levels of fraud taking place on their platforms.
"Our fraud refund guarantee continues to play a vital, often life-changing role in returning money to innocent victims of fraud, who fall foul due to vulnerabilities in other sectors."
Meta is working with Stop Scams UK to help victims and remove scams at the source.
The new Stop. Think. Call. scams awareness campaign was launched by WhatsApp and the National Trading Standards' Friends Against Scams campaign, with support from Citizens Advice.
A Meta spokesperson said: "This is an industry-wide issue and scammers are using increasingly sophisticated methods to defraud people in a range of ways including email, SMS and offline.
"We don't want anyone to fall victim to these criminals which is why our platforms have systems to block scams, financial services advertisers now have to be FCA authorised and we run consumer awareness campaigns on how to spot fraudulent behaviour.
"People can also report this content in a few simple clicks and we work with the police to support their investigations."
What to do if you think you’ve been scammed
If you think a scammer has got hold of your bank details, contact your bank straight away.
You can call the 159 hotline, which will connect you to your bank.
Passwords that have been leaked or compromised should be changed immediately.
Make sure you report scams and fraud to Action Fraud by calling 0300 123 2040, or through the Action Fraud website.
If you're in Scotland, report a scam through Advice Direct Scotland on 0808 164 6000 or on the Advice Direct Scotland website.
You can also report scams to Police Scotland on 101.
For scam emails, forward them to report@phishing.gov.uk, and for scam text messages, forward them to 7726 for free.
If you suspect a scammer is calling you, hang up immediately and search for the contact details online of the place you're supposedly being called from.
Never call back the number provided by the caller.
