The winners of the competition qualified for the 2022–23 UEFA Europa League play-off round.
Teams entered the competition in different rounds, based upon their 2021–22 league affiliation.
Teams from the fifth-level Belgian Division 3 or lower began in round 1, with the exception of six teams from the Belgian Provincial Leagues which were randomly drawn to start in the preliminary round.
This round of matches were played from 14 till 18 August 2021[1] and includes the 79 winners from the Second Round together with 15 teams playing in the Belgian National Division 1 and 2 teams from the Belgian First Division B.
In the end, the matches were spread over multiple weeks, with the final fixture almost a month later on 21 September, mainly to accommodate the teams from the professional leagues which had already started their season.