2017–18 Isthmian League
The 2017–18 season was the 103rd season of the Isthmian League, which is an English football competition featuring semi-professional and amateur clubs from London, East and South East England. It was also the twelfth season for the current incarnations of the Premier, North and South Divisions, the last to have two regional divisions, and the first as the Bostik League following a sponsorship deal with Bostik. In May 2017, the FA chose the Southern League to create one additional division at Step 3 and the Isthmian League to create one at Step 4 as part of  the next change to the structure, and in March 2018, the Northern Premier League voted to reorganise its Step 4 divisions into an east-west alignment, with all Step 3 divisions contracting to 22 clubs and those at Step 4 to 20, taking effect in the 2018–19 season. Premier Division. The Premier Division consisted of 24 clubs: 19 clubs from the previous season, and five new clubs: Billericay Town won the division and returned to National League South after five seasons in the Isthmian League. Dulwich Hamlet, who competed in the Isthmian League since its establishment in 1907, won the  play-offs and followed them. Only one club were to relegate from the Premier Division, Tooting & Mitcham finished bottom of the table and returned straight back to the step 4. At the end of the season a new step 3 division was created under the Southern Football League, seven Premier Division clubs were transferred to the Southern League Premier divisions. Number of clubs in the Premier Division were reduced to 22 for the next season. League table. <onlyinclude></onlyinclude> North Division. North Division consisted of 24 clubs: 17 clubs from the previous season, and seven new clubs: At the  end of the season a new step 3 division were to be created, thus for this season three clubs were to be promoted from each step 4 divisions - champions, runners-up and play-off winners plus one third-placed club with highest points-per-game. Hornchurch won the division and returned to the Premier Division after three seasons in the North Division along with runners-up Potters Bar Town and play-off winners Haringey Borough who never competed at such level. Due to league system restructurisation only one club were to be relegated from step 4 divisions. Norwich United finished  bottom of the table and returned to the Eastern Counties League after two seasons in the Isthmian League. At the end of the season seventh step 4 division was created under the Isthmian League, as the South Division clubs were distributed between new South East and South Central divisions. Four North Division clubs were transferred to South Central Division. Number of clubs in the step 4 divisions were reduced to 20 for the next season. League table. <onlyinclude></onlyinclude> South Division. South Division consisted of 24 clubs: 19 clubs from the previous season, and seven new clubs: At the  end of the season a new step 3 division were to be created, thus for this season three clubs were to be promoted from each step 4 divisions - champions, runners-up and play-off winners plus one third-placed club with highest points-per-game. Carshalton Athletic won the division and returned to the Premier Division after four seasons in the South Division along with runners-up Lewes, who spent in the South Division two seasons after the relegation from Premier Division. Play-off winners Walton Casuals were promoted to the Southern League Premier Division South - the highest level they  competed in their history. Corinthian-Casuals lost in play-off final but were promoted to the Premier Division as step 4 play-off final loser with highest points-per-game ratio after Thurrock from Premier Division folded. Corinthian-Casuals last competed in top division of the Isthmian League in 1973–74 season. Due to league system restructurisation only one club were to be relegated from step 4 divisions. Shoreham finished bottom of the table and returned straight back to the Southern Combination League. At the end of the season seventh step 4 division was created under the Isthmian League, as the  South Division clubs were distributed between new South East and South Central divisions. Number of clubs in the step 4 divisions were reduced to 20 for the next season. League table. <onlyinclude></onlyinclude> League Cup. The 2017–18 Alan Turvey Trophy (formerly the Isthmian League Cup) was the 44th season of the Alan Turvey Trophy, the cup competition of the whole Isthmian League. Calendar. The Isthmian League Cup was voluntary this season, nine clubs decided not to take part in the competition: First round. Sixty two clubs participated in the First round, while one club received a bye to the  Second round: Second round. Thirty clubs to have made it through the First round were entered into the draw with two clubs who get a bye, making thirty-two teams.