The FCA has multiple enforcement powers in this area. In some cases, it could not only take enforcement action against firms and individuals through its usual civil/regulatory enforcement process (based on its own rule book, including the Senior Managers and Certification Regime). It could as an alternative prosecute them before the Crown Court (based on the MLRs and PoCA).
Where a bank's AML controls are perceived as weak, there need not have been actual money laundering before the FCA can take action.
The FCA has made clear in its public messaging over recent months, for example in its 2021-22 business plan, that it is increasingly willing to take a robust position and use litigation to test the extent of its powers.
Being the subject of successful civil/regulatory enforcement action could have severe consequences for a retail bank or member of its staff. However, where the FCA takes action on the basis of the criminal law, the consequences could be even more severe. Apart from reputational damage and the risk of penalties (including fines and, for individuals, the potential for a prison sentence), under English law a criminal conviction could restrict or debar a bank from competing for some types of public contract, affect its ability to obtain or maintain the licences it needs to do business, or end a staff member's career in financial services on the basis that they are no longer fit and proper to carry out a regulated function.
For retail banks operating in the UK and elsewhere, the consequences of a conviction in the UK - under laws outside the UK - could also be severe and unpredictable.