Right now, businesses in the UK and Ireland involved in large-scale mergers and acquisitions are able to notify their deals to the European Commission (EC) for free.

The EC has received over 7,500 notifications over time and has never charged a fee for handling such notifications.

This will change with Brexit because fewer deals – particularly those from the UK and Ireland – would qualify for review post-Brexit by the EC because the level of EU turnover would fall. This means that more deals will have to be reviewed by national authorities in the UK and in the EU rather than the EC.

The EC does not impose a fee for filing a M&A deal. By contrast, the UK's Competition and Markets Authority (CMA) charges fees up to Stg £160,000 for each notification:

Ireland's Competition and Consumer Protection Commission (CCPC) charges €8,000 for each M&A filing irrespective of the size of the parties' turnovers.

So one of the consequences of Brexit for businesses is that M&A deals will become more expensive in terms of filing fees and compliance costs.