[2] In 2001, UEFA proposed three potential formats for a new national team competition, with a first edition tentatively planned for 2004–2007.

In October 2013, Norwegian Football Association president Yngve Hallén confirmed that talks had been held to create a third full national-team international tournament for UEFA members[4] in addition to the FIFA World Cup and UEFA European Championship.

[6] In March 2014, UEFA general secretary Gianni Infantino stated that one of the benefits of the proposal would be to help "less glamorous" national associations arrange games.

[6] The Royal Belgian Football Association's general secretary, Steven Martens, said that lower-ranked nations would still benefit financially from the competition, as the television contract with UEFA would be centralised.

Beginning in 2024–25, the group winners and runners-up of League A advance to a new two-legged home-and-away quarter-final round.

If the aggregate score is level, extra time will be played without the away goals rule enforced, and if it is still tied after extra time, a penalty shoot-out will be used to decide the winner, as per guidelines by the UEFA Executive Committee on 16 December 2021.

[15] The UEFA Nations League trophy was unveiled during the phase draw in Lausanne, Switzerland.

[30] The official anthem of the UEFA Nations League was recorded with the Netherlands Radio Philharmonic Orchestra and Choir, singing in Latin.

[36][37] In February 2012, it was agreed between UEFA and the European Club Association (ECA) that the international friendly schedule would be reduced from 12 to 9 matches a year with the August round of international friendlies in the UEFA confederation abolished from 2015.

[38] The aspiration to eliminate friendlies in favour of a more competitive tournament has been both welcomed and criticised by many football commentators.

UEFA is also keen that European teams will still have the chance to play opponents from other confederations.The format has been criticised for allowing weaker teams to qualify through the Nations League to compete in the European Championship finals, instead of qualifying through the standard qualification process.

[43] However, once the tournament began in 2018, it got applause for "very high-level matches" and impressive turnouts in the initial round of fixtures.

[44][45][46][37] However, criticism against Nations League resurfaced again in 2022 when major footballers like Kevin de Bruyne and Virgil van Dijk condemned the Nations League as "unimportant" and only to glorify some friendlies as well as questioning the calendar due to possibility of injuries.

[48] Croatia international Luka Modrić sparked even wider debate by criticising UEFA for making players play Nations League games so soon after the end of the season.

Also inspired by the recent success of the Nations League, the AFC had begun to formalise a similar competition, planned to begin in 2021 before being stalled due to the effect of the COVID-19 pandemic.