Northern Premier League no relation Bailiwick of Guernsey
Structure
At the top is the single division of the Premier League (level 1, which is often referred to as the "top-flight"), containing 20 clubs. Below the Premier League is the English Football League (EFL) (formerly 'the Football League'), which is divided into three divisions of 24 clubs each: The Championship (level 2), League One (level 3), and League Two (level 4). The 20 clubs in the Premier League and 72 clubs in the English Football League are all full-time professional clubs. The Premier League members are still often referred to as 'League' clubs because, before the establishment of the Premier League in 1992, the Football League, as it was called then, included all 92 clubs, in four divisions. Clubs outside this group are referred to as 'non-League' clubs (i.e. non-EFL), although they too play their football in league competitions.
The top tier of non-League football is the National League.  It contains a national division (National League) (level 5) of 24 clubs, and is the lowest level with a single nationwide league. This division, like the four above, is a full-time professional competition, although some promoted clubs retain part-time status. There are two divisions at level 6, covering the north (National League North) and south (National League South), with 24 clubs each. Some of these clubs are full-time professional and the others are semi-professional. Below the National League, some of the stronger clubs are semi-professional, but continuing down the tiers, soon all the clubs are amateur. Lower-level leagues also tend to cater to progressively smaller geographic regions.
Next down from the National League are four regional leagues, each associated with different geographical areas, although some overlap exists. They are the Northern Premier League (which covers the north of England), Southern Football League Central (which covers the Midlands), Southern Football League South (which covers south and southwest of England, with one club from South Wales) and the Isthmian League (which includes clubs from the south-east of England as well as Guernsey from the Channel Islands). All of the leagues have Premier Divisions of 22 teams (level 7). Below these, and split by region, the Southern Football Leagues has two parallel divisions of 20 teams (level 8). The Isthmian League and Northern Premier League each have three parallel level 8 divisions of 20 teams each.
Level 9 contains the top divisions of a large group of 16 sub-regional leagues. Each of these leagues has a different divisional setup, but they all have one thing in common: there are yet more leagues below them, each covering smaller and smaller geographical levels.
no relation