The Office of the Compliance Advisor Ombudsman (CAO) is an independent accountability mechanism that addresses the environmental and social concerns of individuals and communities affected by projects supported by the International Finance Corporation (IFC) and the Multilateral Investment Guarantee Agency (MIGA), both members of the World Bank Group. Established in 1999, CAO reports directly to the Boards of IFC and MIGA. Operating through three main functions, CAO aims to resolve complaints, enhance environmental and social outcomes, and foster accountability and learning.

Through its dispute resolution function, CAO provides an independent platform for communities and companies to address concerns together and find joint solutions. Their compliance function investigates cases that raise substantial concerns about a project's environmental and social performance. Additionally, their advisory function gathers insights from cases to promote learning and improve IFC and MIGA's environmental and social performance.

CAO works proactively to inform communities, civil society groups, and stakeholders about their work through outreach programs. They also prioritize the safety of complainants and others involved in their processes by addressing threats and incidents of reprisals appropriately. By filing a complaint with CAO, communities and civil society organizations from around the world can seek resolution for issues related to IFC and MIGA projects.

Overall, CAO aims to ensure greater public accountability and improve the social and environmental outcomes of these projects