[1] The season runs from September to April and comprises twenty-two rounds of matches, with each club playing each of its rivals home and away.

[3] Ordinarily Horsham would have dropped to Regional 2 South East but due to obtaining the highest amount of points across those finishing in a relegation place (11th) they earned a reprieve as the demise of Jersey Reds meant there was a corresponding adjustment across multiple leagues.A Promoted into the league are Jersey and Old Alleynians who were promoted as champions of Regional 2 South Central and Regional 2 South East respectively.

Teams leaving the league are the champions Wimbledon, promoted to National League 2 East, while two teams are relegated - RWB (11th position) and Sutton & Epsom (12th) to Regional 2 South Central and Regional 2 Thames respectively.

CS Rugby 1863 and Tunbridge Wells are both transferred from Regional 1 South East.

The new league was made up of teams from both the London & SE and South West divisions.