Criminals will phone you out the blue, pretending to be from a genuine organisation like your building society or bank, the police, or the Financial Conduct Authority.
They convince you that your money is at risk, and you need to move it to a ‘safe’ account straight away. When you do, you realise you can’t access it, and your money is gone.
Don’t allow yourself to be rushed into a decision. Genuine organisations will never ask you to move your money to a safe account.