The Union-wide quantity of allowances issued each year starting in 2013 shall decrease in a linear manner beginning from the mid-point of the period from 2008 to 2012. The quantity shall decrease by a linear factor of 1,74 % compared to the average annual total quantity of allowances issued by Member States in accordance with the Commission Decisions on their national allocation plans for the period from 2008 to 2012. The Union-wide quantity of allowances will be increased as a result of Croatia's accession only by the quantity of allowances that Croatia shall auction pursuant to Article 10(1).

Starting in 2021, the linear factor shall be 2,2 %. 

In 2024, the Union-wide quantity of allowances shall be decreased by 90 million allowances. In 2026, the Union-wide quantity of allowances shall be decreased by 27 million allowances. In 2024, the Union-wide quantity of allowances shall be increased by 78,4 million allowances for maritime transport. The linear factor shall be 4,3 % from 2024 to 2027 and 4,4 % from 2028. The linear factor shall also apply to the allowances corresponding to the average emissions from maritime transport reported in accordance with Regulation (EU) 2015/757 for 2018 and 2019 that are addressed in Article 3ga of this Directive. The Commission shall publish the Union-wide quantity of allowances by 6 September 2023.