Due to the remodeling of the RFEF leagues, as of 2021–22 season the promotion play-off is divided into two stages: regional and national.
Four teams from each group participate in the regional stage, which were classified between places second and fifth of the regular season.
The national stage will be played by 18 teams, which won their respective regional play-offs.
Since 2022–23 season nine different series will be played to determine the winners of the promotion to Segunda Federación.
[2] As of this season, the RFEF recovered the two-legged knockout system, due to the complaints filed against the single knockout system at a neutral venue that had been implemented after COVID-19 and the subsequent reform of the football leagues organized by the RFEF.