The transfer window is the period during a year in which a football club can transfer players from other countries into their playing staff. Such a transfer is completed by registering the player into the new club through FIFA (Fédération Internationale de Football Association). “Transfer window” is an unofficial term mainly used by the media for the concept of “registration period” as described in the FIFA Regulations on the Status and Transfer of Player. According to the rules, each national football association decides on the time (such as dates) of the ‘window’ but it should not exceed 12 weeks. The second registration period occurs during the season and is not allowed to cross the limit of 4 weeks.
FIFA regulates in general that there shall be two windows, a longer one (max. twelve weeks) in the break between two seasons and shorter one (max. one month) in the middle of a season. The specific periods depend on the league’s season cycle and are determined by the national football authorities.
Most major European leagues commence in the second half of the year (e.g. August or September) and stretch over two calendar years to the first half of the next year (e.g. May), resulting in a close season window in the Summer ending in August, and a mid-season window in January.
Although, in England, the transfer window formally opens on 1 July, transfers between clubs in the same association can take place as soon as the last competitive fixtures for the season have been played. However, many transfers can’t be completed until 1 July because players’ contracts expire only on 30 June. Outside of the transfer window, a club can still sign players on an urgent basis, usually if they have no goalkeeper available.
If the last day of a transfer window is on a weekend, the deadline can be extended to the following Monday at the request of those involved for business reasons. The first shift of the deadline since its initiation took place in summer 2008, when the deadline was extended by 24 hours to fall on Monday 1st September at midnight. The transfer deadline in England was likewise extended to 5 PM on 1st September 2009, due to the August Bank Holiday.
Free agents can be signed by a club at any time during the season, if they have been released by their previous club before the end of the transfer window. A club can request to sign a player on emergency basis, e.g. if many goalkeepers are injured at the same time. In England, clubs from the Football League Championship to the Football Conference can loan in players from 8th September to 25th November and also from 8th February until 24th March. An existing loan deal can be made permanent at any time outside the transfer window.
The day on which a window closes is known as transfer deadline day & is usually one of the busiest days of the window, generating a flurry of transfers, often because a number of interdependent transfers are completed resembling a housing chain, generating much media & fan interest specially on social media.