Member States of the United Nations adopted the 2030 Agenda for Sustainable Development, containing 17 Sustainable Development Goals (SDGs) and 169 targets. SDG 12 Sustainable Consumption and Production in its Target 12.6 explicitly encourages companies to adopt sustainable practices and to integrate sustainability information into their reporting cycles. Indicator 12.6.1 requires data on the number of companies publishing sustainability reports. Since 2015 UNCTAD has been working to enable further advancements on SDG sustainability reporting by companies. Specifically, focusing efforts to support governments in measuring the contribution of the private sector to the implementation of the SDGs. UNCTAD developed its Guidance on core indicators for entity reporting on contribution towards implementation of the Sustainable Development Goals (GCI). This Training Manual has been updated based on the changes included in the second edition of the Guidance on Core Indicators for Sustainability and SDG Impact Reporting. The core SDG indicators cover the economic, environmental, social and institutional areas. They were identified based on key reporting principles, main reporting frameworks and companies reporting practices