This chapter focuses on the formal design of European Aviation Safety Agency's (EASA) international cooperation without ignoring the legal-policy environment within which the agency is operating. It takes into account the relevant legal and institutional framework of the Union, focusing on the external dimension of the European Union aviation policy area. The international cooperation mandate and tasks of EASA are to be integrated within the overall framework and objectives of its Founding Regulation. According to EASA's internal procedure, concluding a working arrangement with a competent authority from a third country or with an international organisation entails three distinct phases: initiation; drafting and negotiation; and conclusion, communication and publication. Under the Bilateral Air Safety Agreements (BASA) with the USA, Canada and Brazil, two different instruments have been concluded by EASA with the corresponding aviation authority, each being linked to one of the two Annexes of the respective BASA.