The 2025 summer transfer window promises to be another busy period. However, due to the influence of the FIFA Cup World Cup it will look a little different to usual.

The first games are being played on June 15, and the clubs involved need to be able to sign players to take part. So FIFA have given member associations with clubs in the Cup World Cup the right to apply an additional registration period from June 1 to 10, though there is no obligation to do so.

In addition, FIFA has a clause in the Club World Cup regulations which allows clubs to replace players on their squad lists whose contracts have naturally expired in the period June 27 to July 3, which may also influence transfer business.

Usually, most leagues in Europe open their windows on July 1, while the general deadline for closing is one day later than usual -- on Monday, Sept. 1 -- because Aug. 31 falls on a Sunday.

The closing date was set following discussions between the top five European leagues. Other associations can still choose to end the window at a later date than Sept. 1.

Clubs in all leagues will still be able to sign players as free agents after the deadline, and as long as they are not officially attached to any club when the window closes.

Deals can be agreed between leagues with transfer windows which are closed. They will be officially completed if or when the signing club's window is open.