According to Article 102 bis of NOIF (Norme Organizzative Interne della F.I.G.C),[1] the co-ownership deal must be confirmed each year.
The deal may expire, be renewed, or one of the co-owners can buy back the other 50% of the player's rights.
Deals that failed to form an agreement after the deadline, will be defined by auction between the 2 clubs: both clubs will submit their bid in a sealed envelope.
Non-submission means the player's rights go to the other team for free.
The mother club could sell their rights to third parties in a loan deal, like Emiliano Viviano in 2010 and Massimo Volta in 2007.