UEFA's 55 nations have been split into five groups of six teams and five groups of five. Each team plays home and away against the other teams in their group with the top two from each section becoming the first 20 teams to qualify.
The traditional qualifying groups are the easy part, deciding the contestants for playoffs to decide the remaining four places is a rather more complex process.
Kane welcomes great expectations on England
UEFA's inaugural Nations League played in the Autumn of 2018 split the 55 members into four tiers (League A-D) with four groups in each.
The 16 Nations League group winners have the safety net of a playoff but will only take part if they fail to make the top two in their qualifying group.
Those 16 nations are:
League A: England, Netherlands, Portugal, Switzerland
League B: Bosnia and Herzegovina, Denmark, Sweden, Ukraine
League C: Finland, Norway, Scotland, Serbia
League D: Belarus, Macedonia, Georgia, Kosovo
Each league will have a path of its own, all of which will feature two single-leg semi-finals and one single-leg final. The winner of each path will qualify for Euro 2020.
All nations were ranked 1-55 on their Nations League performance based on where they finished in their group, points won, goal difference etc.
If a Nations League group winner also finishes in the top two of their qualifying group, their spot will go to the next best-ranked team in their league.
Gambling Germany boss Loew goes all-in ahead of Serbia friendly
As group winners in League A, England, the Netherlands, Portugal and Switzerland will contest the first Nations League finals in June.
The outcome of the finals will have no impact on who qualifies for Euro 2020.
All qualifying matches will be played between March and November 2019, with double-headers in March, June, September, October and November.
Those sides involved in the Nations League finals will not have any qualifiers in June.
The 12 host cities are: Amsterdam, Baku, Bilbao, Bucharest, Budapest, Copenhagen, Dublin, Glasgow, London, Munich, Rome and Saint Petersburg.
The tournament will take place between June 12 and July 12, 2020.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ