In the transition towards open access, institutional publishing is challenged by fragmentation and varying service quality, limited visibility, and sustainability. In this workshop we will pay special attention to ‘Diamond’ models of publishing that are scholar-led and owned and do not charge fees for reading or publication to either readers or authors. This workshop, hosted by DIAMAS project, presents current project results and discusses the following issues: Coordinating and improving the efficiency and quality of institutional publishing by co-creating an Extensible Quality Standard for Institutional Publishing (EQSIP) with various scholarly communities. This quality framework will contribute to professionalizing, strengthening and reducing the fragmentation of institutional publishing in the European Research Area (ERA). Building institutional publishing communities of practice and co-creating a Common Access Point, institutional publishing registry, publishing guidelines, training materials, self-assessment tools, knowledge exchange hub and collaborative tools. Building and enabling the financial sustainability of institutional publishing, co-creating diamond OA financial models and shared cost frameworks. Formulating community-led, actionable recommendations and strategies for institutional leaders, funders/sponsors/donors, and policymakers in the ERA on diamond OA.