The European regulatory framework throughout the Directive 2009/28/EC on renewable energy encompasses several sectors in the field of usage of renewable energy, such as electricity generation, production of energy for heating and cooling and the usage of biofuels and electricity from renewable energy sources in transport. One of the requirements of the Directive is the implementation of Guarantees of Origin system for electricity pursuant to the obligations under Directive 2009/72/EC on the publication of information about the origin of the primary energy sources. EU has defined a Guarantees of Origin in European legislation, in order to allow trade of electricity produced from renewable energy sources and additionally, to guarantee the customers transparency in the purchase of such energy. Guarantees of Origin provided the electricity a "green" label, i.e. guarantee that producer has produced a certain amount of electricity from renewable energy sources. In addition, Directive 2003/54/EC obliged all EU Member States to implement through its legislation the scheme for the disclosure of the fuel mix. Implementation of Guarantees of Origin system is standardized which finally resulted in a free, simple and transparent Guarantees of Origin trade. Guarantees of Origin are recognized as the only tool for the disclosure of information on the primary energy sources. The Guarantees of Origin system has been successfully implemented in Croatia in 2015, when the first Guarantees of Origin for domestic electricity production were issued. Financial analysis shows that the further registration of production facilities in the Croatian Guarantees of Origin Registry is expected as well as entry of new market participants, primarily suppliers who will increasingly offer to end customers tariff models with electricity guaranteed structure, which all will in the end result in increased Guarantees of Origin market liquidity in the Republic of Croatia and the increased usage in practice.