League A consists of the 12 top-ranked teams: Germany, Portugal, Belgium, Spain, France, England, Switzerland, Italy, Poland, Iceland, Croatia and the Netherlands.
The leagues are compiled based on the teams' positions in the UEFA national team rankings.
Teams will be split into four groups of three.
At the end of the qualifying round for the world Cup formed a part of the divisions of the first draw of the League of Nations - a tournament created to replace global friendlies.
In order to counteract what many view as meaningless worldwide friendlies, UEFA have established the Nations League, which will be played off between teams of similar standards. Instead that will be delayed, and start in March 2019 and end in November of that year - the qualifying draw does not take place until December 2018. The Finals consist of four matches - semi-finals, third-place match and final - to be played in one of the finalist countries. This is a separate competition to the Euro 2020 qualifiers.
The other 43 European nations will be spread across three other Leagues B, C and D - the group winners will be promoted to replace the nations finishing bottom of Leagues A, B and C for the next Nations League which begins in September 2020.
Teams will be split into one group of three and three groups of four.
League C: Hungary, Romania, Scotland, Slovenia, Greece, Serbia, Albania, Norway, Montenegro, Israel, Bulgaria, Finland, Cyprus, Estonia and Lithuania.
The group winners in Leagues B, C and D will gain promotion and those who finish bottom of the groups in Leagues A, B and C will be relegated.
Teams will be drawn into four groups of four.
The Euro 2020 qualification play-offs are set for March 2020 as mentioned above, and Euro 2020 itself, which will be played across the continent, will begin three months later.
March 2020 will see the play-offs for Euro 2020, with the final tournament to be held in 13 cities across Europe, including Dublin, in June-July.