Supply-chain due diligence is increasingly becoming a business reality and a regulatory requirement. The most recent example for mandatory regulation is a proposal by the European Parliament to translate the Organisation for Economic Co-operation and Development’s Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High-Risk Areas into law. The draft rule sheds light on a number of trade regulatory mechanics of supply chain due diligence. This article explores essential elements that assure due diligence’s effectiveness and coherence with existing trade regulation.