In June 2021 the European Public Prosecutor’s Office (EPPO) will become operational. This new EU body has an unprecedented, profoundly hybrid structure. To conduct its investigations, the EPPO will need to rely on existing national authorities (eg police, customs, judges) and, to a large extent, also domestic law as Regulation 2017/1939 only provides for some common rules of criminal procedure. This triggers many legal and practical challenges (eg the way in which case files are handled). To turn the EPPO into a success, continuous loyal cooperation between the central level and the decentralised level will be indispensable. This is only possible if there is sufficient mutual trust between both levels. This paper will exam vectors of trust and distrust in the EPPO’s structure and how it is currently being implemented at EU and national level, to make further proposals for its operational success.