 Eleven of the teams listed below participated in the 2012–13 National League 2 South season.Cambridge were relegated from National League 1; London Irish and Exmouth were promoted from National League 3 South West; Bishop's Stortford were promoted from National League 3 London & SE; Ampthill were promoted from National League 3 Midlands and were then level transferred from National League 2 North (where they would normally have expected to play) due to an imbalance in the number of teams in the two fourth tier leagues.Each season, the runners–up in the National League 2 South and National League 2 North participate in a play–off for promotion into National Division 1.