Bank of Ireland is urging people to be wary of any requests to change bank account details or transfer funds.
The bank says people need to be particularly cautious of anything that says it’s from a supplier or senior management asking for details to be changed.
Paul O’Brien from Bank of Ireland’s fraud team says the emails can seem very legit.
"You will get an email that appears to be from a trusted supplier, and it will say something like, you know, we need you to update your account details that you hold for us, or, you know, here's our new business accounts that we need you to pay money into."