In professional association football, a free transfer, also known as a Bosman transfer, involves a professional association football club releasing a player once the player's contract has expired or made available just before the end of the contract.
How it works
The club acquiring the player does not have to pay any compensation for their release due to having nothing left to pay on their contract, hence, the term free transfer. Some individual leagues have restrictions to protect academies. For example, in the UK, players under 24 who are out of contract are only available on a free transfer if released by the club holding the players' licence.
With six months or less remaining on an existing contract for players aged 23 or older, they are free to negotiate with other clubs and sign a pre-contract agreement, indicating their ability to move to their intended club on a Bosman transfer once the next transfer window opens.
Free transfers are common in leagues where money is less commonly available for clubs to spend on transfer fees. It is also common for players to leave wealthy clubs on a free transfer if the club cannot offer first team football, especially when departing for clubs in lower leagues.