Charlton may have to wait until June to find out if they have qualified for the Uefa Cup next season.
The Addicks are third behind Chelsea and Arsenal, both Champions League-bound, in England's Fair Play League.
The leading country in Europe's Fair Play League gets an entry to the Uefa Cup while two places are drawn from countries on more than eight points.
The European League ends on 31 May and Uefa, the continent's governing body, will name the winners on 8 June.
Charlton's chances of reaching Europe through their Premiership position were all but ended on Saturday when Aston Villa and Liverpool won.
The Addicks are six points adrift of fifth place - the final European qualification spot - with two games remaining.