Premier League clubs are permitted to conduct the purchase and sale of players during the winter and summer transfer windows.
Windows were introduced as part of a compromise agreement with the European Commission about how the whole transfer system worked and how it could best preserve contractual stability for both the player and the club while allowing movement at prescribed times during the year – the summer and winter transfer windows in effect.
The alternative was to bring football in line with most other industries where contracts were not enforceable or liable for appropriate compensation, i.e. notice periods being served and players moving at will. The football authorities across Europe felt this would fatally undermine the footballing economy and remove the incentive for clubs to invest in developing players.
The Winter Transfer Window usually opens on the first day of the New Year and closes at 11pm GMT on the last day of January.
The Summer Transfer Window usually opens on 10 June and from the 2018/19 campaign, will close at 5pm BST on the Thursday before the start of the season.
Manchester United – Summer 2017 Transfer Window
Transfer windows In
Transfer windows Out
Josh Harrop (Preston North End) Free Details
Regan Poole (Northampton) Loan Details
Wayne Rooney (Everton) Undisclosed Details
Dean Henderson (Shrewsbury) Loan Details
Adnan Januzaj (Real Sociedad) Undisclosed Details
Sam Johnstone (Aston Villa) Loan Details
Devonte Redmond (Scunthorpe United) Loan Details
Cameron Borthwick-Jackson (Leeds) Loan Details
Timothy Fosu-Mensah (Crystal Palace) Loan Details
Guillermo Varela (Penarol) Undisclosed Details
Matty Willock (Utrecht) Loan Details
Andreas Pereira (Valencia) Loan Details