British Gas customers in Sheffield are being urged not to fall for fake emails that claim they are owed a refund.
The phishing message claims accounts will stop working within 24 hours if you don't click on a "get your refund" link.
READ MORE: South Yorkshire's Barry Chuckle dies aged 73
Customers who click are directed to a website that asks them to fill in their personal details, under the impression that they will be able to get some money back.
But the website is in fact run by scammers hoping to trick customers into handing over their bank details.
Action Fraud issued a warning about the scam after the organisation received "lots" of reports of the same email.
READ MORE: Thug spat at hospital security guard as nurses were trying to help him
Their advice states: "Always question unsolicited requests for your personal or financial information in case it's a scam.
"Never automatically click on a link in an unexpected email or text."
READ MORE: Fire at power station on outskirts of Sheffield
Customers who receive the scam email should not click on it and are asked instead to report it to Action Fraud on 0300 123 2040.