Premier League clubs have already spent more in four days this summer - a total of £185.5m - than the entirety of the January transfer window.
Top-flight teams have been scrambling towards what has been described as the 'unofficial transfer deadline day' on Sunday and more deals are being announced on Monday.
To avoid charges and possible points deductions clubs must be compliant with profit and sustainability rules (PSR) - and 30 June was a key date.
The summer transfer window does not officially close until Friday, 30 August but, as Nottingham Forest discovered to their cost last season, some Premier League clubs needed to get business done earlier.