FA rules, UEFA Regulations and FIFA Regulations Governing International Matches require all affiliated clubs at all levels of the game to obtain the consent of The Association to play in a friendly match or tournament against a non-English team irrespective of where the match is to be played. Consent is also required for two English teams to play a friendly match against each other outside of England. This includes friendly matches and tournaments, training matches and so called behind closed doors matches.
Depending on the level of the teams involved the consent of UEFA, any other confederation involved and the national association of the opposing club may also be required.