The relevant test in the EU ETS Directive for an aircraft operator is simply that there is a legal person responsible for flights arriving or departing from EU aerodromes which are not covered by the exemptions in Annex I of the EU ETS Directive. Individual companies that have been duly incorporated each possess their own distinct legal personality. It follows, therefore, that each company responsible for flights covered by Annex I is a different aircraft operator for the purposes of the EU ETS Directive even if they are in the same corporate group of companies.

In addition, Article 18(a) of the EU ETS Directive identifies an administering Member State, in relation to a particular commercial aircraft operator, by reference to the mandatory operating licence issued to that operator by the Member State concerned. There is a presumption, therefore, that each legal person issued with an operating licence by a Member State should be treated as a distinct and separate aircraft operator.