It started on 17 October 2020 with the first round of the regular season and ended on 16 May 2021 with the promotion playoffs.
Consequently, the competition systems were adapted to the growth of the number of teams with a series of independent modifications in each of the five conferences.
[2] The Conference A consisted of 3 groups of 11 teams from Galicia, Asturias, Cantabria, Castile and León, Navarre, La Rioja and Basque Country.
[3] The Conference B consisted of 17 teams in 2 groups from Canary Islands, Castilla–La Mancha and Community of Madrid.
[5][3][6][7] The Conference D consisted of 2 groups of 11 teams from Andalusia, Extremadura, Ceuta and Melilla.