I got this off the Fa website. Article 19 Protection of Minors
1. International transfers of players are only permitted if the player
is over the age of 18.
2. The following three exceptions to this rule apply:
a) The player’s parents move to the country in which the New Club
is located for reasons not linked to football
b) The transfer takes place within the territory of the European
Union (EU) or European Economic Area (EEA) and the player is
aged between 16 and 18. In this case, the New Club must fulﬁl
the following minimum obligations:
i. It shall provide the player with an adequate football education
and/or training in line with the highest national standards.
ii. It shall guarantee the player an academic and/or school
and/or vocational education and/or training, in addition
to his football education and/or training, which will allow
the player to pursue a career other than football should he
cease playing professional football.
iii. It shall make all necessary arrangements to ensure that the
player is looked after in the best possible way (optimum living
standards with a guest family or in club accommodation,
appointment of a mentor at the club etc.).
iv. It shall, on registration of such a player, provide the relevant
Association with proof that it is complying with the
aforementioned obligations; or
c) The player lives no further than 50km from a national border,
and the club for which the player wishes to be registered in the
neighbouring Association is also within 50km of that border.
The maximum distance between the player’s domicile and the
club’s quarters shall be 100km. In such cases, the player must
continue to live at home and the two Associations concerned
must give their explicit consent.http://www.thefa.com/TheFA/RulesandRegulations/~/media/Files/PDF/TheFA/PlayerRegistrations/transfer_commentary_06_en_1843.ashx/transfer_commentary_06_en_1843.pdf