However, National League clubs which formed independent federation were reluctant to invest for their professionalization, and the plan was miscarried due to their refusal.

[1] The Korea Football Association (KFA) continued its plan to complete the South Korean football league system.

[3] All participating clubs play home and away season in the K3 League.

The championship playoffs were contested by top four clubs of the regular season in 2020 and 2021, but were not held in 2022 onwards.

The promotion and relegation system exists between the K3 League and the K4 League, although the number of promoted team(s) and relegated team(s) is different every season.