The Horizon 2020 open access mandate outlines requirements for project coordinators and researchers to ensure free online access to all peer-reviewed scientific publications associated with H2020 results. Beneficiaries must deposit publications in a designated repository, ensuring immediate access or adhering to specified embargo periods, and may choose between two open access routes: green (self-archiving) or gold (open access publishing). OpenAIRE provides tools and support for compliance with these requirements, including a framework for managing metadata and reporting within the project lifecycle.