The IFA has written to Fifa to express concern after several Northern Ireland born players have opted to play for the Republic of Ireland Under-21 squad.
Howard Wells has written to Fifa
A statement from the IFA said chief executive Howard Wells was seeking "advice and clarification" from the game's governing body.
Wells raised the issue of player nationality at an IFA Executive Committee meeting on Tuesday night.
Tony Kane and Michael O'Connor were in the latest Republic Under-21 panel.
The two Belfast natives were named in Don Givens' squad for a friendly match against Luxembourg.
They join another Northern Ireland player, Manchester United's Darren Gibson, in swapping allegiance.
O'Connor has represented Northern Ireland on six occasions at under-21 level.