According to the famous Bosman decision of 1995, players can enter into preliminary contracts up to six months before their contracts expire. At present, players appear to be able to stay with their clubs until the 2019/20 campaign reaches its conclusion, regardless of when their contracts expire. In 2013, the France Nantes team obtained a blocking of two transfer windows after signing the rules for striker Ismael Bangoura of the Emirati club Al Nasr in 2012.  It was decided that Nantes had convinced Bangoura to break his contract with the UAE team and had been sanctioned by FIFA with a fine of 4.5 million euros to be paid to Al Nasr.  After a first pardon, the ban was upheld.    Given that there are six months or less of an existing contract for players 23 years of age and older, they are free to negotiate with other clubs and sign a preliminary contract indicating their ability to change clubs in the event of Bosman`s transfer when the next transfer window opens. Although usually a preliminary contract is signed to ensure the future registration of a player, an agreement can be obtained where the club, who receives the registration, can pay a fee to the other club to sign the player earlier, as was the case in January 2013, when Schalke 04 midfielder Lewis Holtby, who remains six months on his contract, signed a preliminary contract with Tottenham Hotspur, but at the end of the month Tottenham paid a $1.5 million transfer fee.  Fifa rules stipulate that a club that wants to enter into a contract with a professional must inform the current club in writing before entering into negotiations with them. A professional can only enter into a contract with another club if his contract with his current club has expired or expires within six months. In 2005, Italian roma secured a one-year transfer deal from FIFA, starting on 1 July, when French centre-forward Philippe Mexes joined the club in September 2004, while still under contract with Auxerre.
  In December 2005, the ban was reduced at the request of the CAS, which ended after the transfer window in January, but the CAS confirmed that Roma had “not only encouraged Mexes to break his contract with Auxerre, but was actively causing the break”.  Both had been out of contract with Tottenham and Manchester United this summer – and could have signed a preliminary contract with the Italian giants. The club that receives the player does not have to pay compensation for his dismissal, because he no longer has to pay anything on his contract, hence the duration of the free transfer.