On 3 April 2017, the Council adopted a regulation aimed at stopping the financing of armed groups through trade in conflict minerals. The regulation obliges EU companies to source their imports of tin, tantalum, tungsten and gold responsibly and to ensure that their supply chains do not contribute to funding armed conflict. These 'due diligence' rules will become binding from1 January 2021, though importers are encouraged to apply them as soon as possible….The regulation carries clear obligations to source responsibly for the 'upstream' part of the production process, which involves the extraction and refining of these minerals... The competent authorities will carry out checks to ensure that EU importers of minerals and metals comply with their due diligence obligations…The Commission will also draft a handbook including non-binding guidelines to help companies, and especially SMEs, with the identification of conflict-affected and high-risk areas. The regulation builds upon 2011 OECD guidelines which set the international benchmark for supply chain due diligence...