The U2Demo Horizon Europe project is deeply committed to the principles outlined in the European Commission´s Open Research Data Management guidelines, to enhance the accessibility and reusability of research data generated within European Commission-funded projects. In line with these principles, U2Demo consortium is dedicated to develop tools and platforms that are open-source and align with the principles of openness, technology neutrality, interoperability, replicability, reliability, security, trustworthiness and scalability, to make them reusable by the broader research community and stakeholders. In this context, U2Demo will follow a comprehensive Data Management Strategy detailed in this deliverable – the Data Management Plan (DMP), D8.3. This initial plan – compliant with the FAIR (Findability, Accessibility, Interoperability, and Reusability) principles and the European Commission´s guidelines on Open Science, has been prepared by Work Package (WP) 8 leader – INESC ID. This plan will be updated at M24 (D8.4) or whenever changes are applied.This document serves as a key resource for outlining the types of data outputs generated within the project, specifying data formats, sources, storage (short- and long-term duration) mechanisms and documentation processes. The DMP will provide guidelines on how data will be managed, storage and preserved throughout the project lifecycle. This plan aligns with the European Commission´s priorities on Open Science, including open access, data transparency, reproducibility, accessibility, security and reliability of the research outputs. Additionally, it ensures compliance with GDPR rules on data access, data sovereignty and data protection, safeguarding ethical and legal considerations. Finally, to facilitate effective data management and monitoring, the deliverable will be complemented by a Data Definition Catalogue (DDC), a data management monitoring Excel file. The DDC will be continuously update by the Project Manager, with support from the WP and Task leaders. The DMP main goal is to provide clear guidance to all project partners and to foster responsible data management practices, to maximize the impact of the research outputs.