The Kimberley Process Certification Scheme (KPCS) for rough diamonds came into effect on January 1, 2003. Over 45 countries, plus all those represented by the European Community, participate. Under the terms of the KPCS, each participating government agrees to issue a certificate to accompany any rough diamonds being exported from its territory, certifying that the diamonds are conflict-free. Each country must therefore be able to track the diamonds being offered for export back to the place where they were mined, or to the point of import, and it must meet a set of standards for these internal controls. All importing countries agree not to allow any rough diamonds into their territory without an approved KPCS certificate.
Given the large volume of diamonds being traded across borders, it was deemed necessary to produce trade and production statistics which can be compared from time to time in order to ensure that the diamonds leaving one country match those entering another, by volume and by value. Working groups comprising representatives of governments, industry and NGOs deal with statistics, monitoring, technical issues and membership in the KP. A peer review mechanism has also been created, and more than 30 country reviews had been undertaken by October 2006. During 2006, a "Three Year Review" of the overall KPCS was carried out, examining its impact and the effectiveness of its various systems and processes.