Within the Netherlands, 24 geothermal systems have been realized of which 16 are operational, together producing 3.4 PJ of heat in 2018 (status date 1-1-2019). The main application domain is horticulture. The ambition of the Dutch government is to see production of geothermal energy increase in the Netherlands to 50 PJ in 2030, subsequently 200 PJ in 2050 and also to expand the application domain to district heating and industry. A state of the art resource assessment can support the Dutch government policy to realize its ambition. By classifying the resources based on project maturity including reference to the obstructing issues in the maturation of projects such as technical, financing, licensing and or social and environmental complexities targeted policy can be drafted. As of January 2019, 51 exploration licenses have been granted, and 31 more have been applied for (MEA2019). At least one geothermal project is defined in each of these exploration licenses, at different levels of advancement. Outside the boundaries of existing licenses and licenses under application, the Netherlands provides ample space for geothermal development. At the moment, there are no tools or practical methodologies to integrate all available information in a coherent and automated manner. As such, a method to quantify the geothermal energy resources of projects ‘not yet realized’ using the United Nations Framework Classification (UNFC) resource classification system would help policymakers to decide upon the most appropriate measures to remove obstructions for reaching the 2030-2050 geothermal ambitions. In this study, we show the initial results of a resource assessment and classification system for geothermal energy while incorporating environmental and social issues in the classification, as required by the UNFC2009. As basis for this resource assessment, we use the web tool ThermoGIS-v2.1 (Vrijlandt et al. 2019). ThermoGIS-v2.1 using information on the Dutch subsurface derived from the regional mapping by the Geological Survey. It is updated through incorporation of newly gained insights and data and provides a comprehensive overview of the geothermal potential for a selected set of aquifers. The resource estimates, including the uncertainty range related to these figures, at the status date 1-1-2019 of the Dutch geothermal “project portfolio” are classified using UNFC, resulting in a set of resource figures per resource class according to project maturity: commercial, potentially commercial, non-commercial and exploration projects. @en