1.All assigned amount units issued for the second commitment period available in the Union registry after the Union has complied with its obligation laid down in Article 11(3) of Regulation (EU) No 525/2013 and after any transfer of assigned amount units pursuant to implementing acts adopted on the basis of Article 10(7) of Regulation (EU) No 525/2013 has been carried out (‘Union surplus’) shall be returned to the Member States at the end of the second commitment period.