The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) was set up in 1996 with its headquarters in Vienna, Austria. It is an interim organization tasked with building up the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in preparation for the Treaty's entry into force, as well as promoting the Treaty's universality.
Its provisional secretariat has nearly has nearly 300 multi-disciplinary professional and support staff from around 90 Member States.
The CTBTO is financed mainly through assessed contributions by Member States. Its budget in 2022 is US$125 920 000.
The Commission consists of two main organs: