This report provides practical guidance for the implementation of project-related multilateral cooperative compliance programs. In an era of ever-evolving business models and financial relations among countries, with large volumes of cross-border transactions, it is important to ensure that taxpayers enjoy greater and faster tax certainty when doing business across the borders, while tax administrations should be in the position to assure the collection of their tax revenues in an effective manner. Multilateral cooperative compliance is a cross-border dispute prevention mechanism that can contribute to building transparent and trust-based relationships between tax administrations and taxpayers, thereby fostering cross-border trade and investment. Ultimately, it has the potential to lead to more sustainable tax systems. The Report contains relevant policy considerations, best practices, and legal issues that should be considered when designing a multilateral cooperative compliance program. It addresses practical challenges and contains an implementation package to support tax administrations, policymakers, taxpayers, and other stakeholders that envisage developing or participating in such programs.