In order to be eligible to participate in the competition, players must be registered with UEFA to play for a club within the deadlines set out in these regulations, and must fulfil all the conditions set out in the following provisions.
Each player must be duly registered with their national association as playing for the club concerned in accordance with the association’s own rules and those of FIFA, notably the FIFA Regulations on the Status and Transfer of Players.
Each player taking part in the competition must be in possession of a player registration licence issued by the player's association or a valid passport or identity card, each containing the player's photograph and full date of birth (day, month, year). The referee or the UEFA match delegate may ask to see the passports/identity cards of the players listed on the match sheet.
All players must undergo a medical examination to the extent provided for in the UEFA Medical Regulations.
A player may not play in the UEFA Champions League, UEFA Europa League or UEFA Conference League for more than one club in a single season. Exceptionally, any player who has been fielded in the first, second or third qualifying round or the play-offs of the UEFA Champions League, UEFA Europa League or UEFA Conference League is entitled to play in the UEFA Champions League, UEFA Europa League or UEFA Conference League for another club as from the league phase. As from the start of the knockout phase, players can be registered in accordance with Article 32. A substitute player who has not been fielded is entitled to play for another club competing in the UEFA Champions League, UEFA Europa League or UEFA Conference League in the course of the same season, provided that this player is registered with the UEFA administration in accordance with the present regulations.
The UEFA administration decides on questions of player eligibility. Challenged decisions are dealt with by the UEFA Control, Ethics and Disciplinary Body.