Innovative instruments intended to regulate the private security industry at the international level, such as the Montreux Document and the International Code of Conduct for Private Security Service Providers (ICoC) and its Association (ICoCA), have emerged over the past years. While addressed to different actors, the Montreux Document and the ICoC share the principle objective of enhancing private security company (PSC) compliance with applicable rules of international humanitarian law and international human rights law. However, effective implementation remains a challenge. One reason is that the potential synergies between the two processes may not yet be fully appreciated. This paper provides a detailed comparison between good practices contained in the Montreux Document and the ICoC principles. In particular, it examines to what extent states may build on the ICoC and its Association in order to regulate the provision of private security services effectively and thereby implement good practices identified in the Montreux Document. The paper recommends that states include ICoCA membership in their national authorisation or hiring processes. The principles of the ICoC and the governance mechanism established by the ICoCA can complement or even be an essential component of a state’s effort to regulate PSCs in accordance with Montreux Document good practices.