This guide outlines the Basel IV implementation requirements as established by the European Commission on 27 October 2021. It details the legislative package that finalizes the Basel III reforms, now referred to as Basel IV, which includes the Capital Requirements Regulation 3 (CRR III) and the Capital Requirements Directive 6 (CRD VI). The document emphasizes the urgency for banks to prepare for the January 2025 implementation deadline. Key revisions introduced by CRR III and CRD VI are presented, including updates to credit risk approaches, market risk requirements, operational risk standards, and enhancements in disclosure related to Environmental, Social, and Governance (ESG) risks. The guide stresses the importance of early preparation for banks to effectively manage the transition and mitigate associated risks. It also highlights the need for comprehensive testing and validation of systems to ensure compliance with the new regulations. The document serves as a resource for banks to navigate the complexities of Basel IV compliance.