As this is a Reserve league, movement between Divisions One and Two is dependant upon the fortunes of the Senior side. As an example it is possible for a team to win the league but not be promoted if the Senior side do not finish in the top two places.
At the end of the 2010–11 season there were 26 teams, contained within two leagues. Sure Mobile Combination One contained 13 teams, with CFS Combination Division Two catering for the remaining 13. There were 27 teams until the 2008–09 close-season saw the demise of Northern Athletic F.C..