These are often carried out over the phone or via email, with a criminal pretending to be your bank or building society. Normally they will suggest that there is an issue with your account and that they need to confirm some information about you. If a person is asking for personal details over the phone, you should hang up immediately. Banks would never ask for details such as your name, address, or payment details over the phone or by email.
If the individual suggests that you call them back, it is still part of a scam. They won’t hang up their phone and therefore still be connected to you phoneline to listen in to conversations you conduct after this point.
It is important that you never disclose your PIN to anybody and do not provide bank details to cold callers or unknown emails.