FIFA's rules allow a player to switch the nation they represent for a number of reasons.
Inter Milan striker Ange-Yoan Bonny is among the latest players to officially switch nations, transferring from France to Ivory Coast ahead of this summer's World Cup.
Ivory Coast are competing at the tournament, meaning Bonny could feature if called up to the squad.
In order to do so, players must be eligible to play for the nation they are switching to.
There are five different sets of circumstances in which a player is eligible to switch nations.
A new rule introduced in 2021 allowed players who had played up to three senior international caps prior to the age of 21 to switch nations.
Previously, the rule stated that players could not switch nations once they had earned a senior cap in a competitive match.
England midfielder Declan Rice benefited from this rule when switching from the Republic of Ireland.
Rice won three senior caps for the Republic, all of which came in international friendlies, before opting to instead play for England in 2019.
Former Chelsea striker Diego Costa also swapped nations to Spain in 2014, having played for Brazil in two friendly matches in 2013.
How can a player switch nationalities?
While FIFA sets guidelines for nations and players in their rules on switching nationalities, it is ultimately the responsibility of all of FIFA's 211 members to individually ensure the players they are registering are eligible.
There are five different sets of circumstances in which a player can become eligible to switch nationalities.
The player has played for the country they are leaving only at youth level and was already dual-registered to the country they are joining
The player has played for the country they are leaving only at youth level, was not dual-registered to the country they are joining, their last international appearance for the country they are leaving came prior to the age of 21, and meets article six or seven of FIFA's player eligibility guidelines
The player played for the country they are leaving at senior level, were dual-registered with the nation they are joining whilst making their debut for the nation they are leaving, have not played for the country they are leaving since before turning 21, have not played more than three times for the country they are leaving at senior level, three years have passed since their last international appearance, and they have not played for their first nation at a major tournament
The player wishes to represent a nation that were not FIFA members when they made their debut for the nation they are leaving, have not played for their first nation since the second nation became FIFA members, were either dual-registered or obtained nationality with the nation they wish to join as soon as reasonably practical, and meets article six or seven of FIFA's player eligibility guidelines
The player has played in a senior match for their first nation but then permanently loses their nationality without their consent due to government authority and holds the association they wish to represent
