In 2006, the first season, 10 clubs played each other twice, with promotion going to the championship winner Chula-Sinthana FC.
The league was again split from 2 groups into 5 groups 52 clubs played covering the North of Thailand, North East (Isan) region, Central East Zone, Bangkok central zone and South of Thailand.
5 group winners would enter a championship round to determine which three teams would gain promotion to the Thai Division 1 League.
To participate a club must have held an associate membership, and then passed an inspection in order to obtain a participation licence issued by Football Association of Thailand and passed club licensing regulation.
Due to the epidemic of Coronavirus disease 2019 also known as COVID-19, the season must be postponed to start in late 2020 and end in early 2021.