Context Invasive alien species are an important driver of biodiversity loss. Policy responses are developed to address this threat and need to be based on the best available data, including information from alien species registries and occurrence data. The Tracking Invasive Alien Species (TrIAS) project implemented a indicator workflow based on FAIR principles to feed policy relevant indicators for biological invasions in Belgium from openly published checklist and occurrence data on GBIF. Description This dataset contains the outputs of the pipeline that prioritizes alien species based on their emergence status. This prioritization is built upon the information contained in: The Global Register of Introduced and Invasive Species - Belgium (GRIIS Belgium) which is published by the IUCN Invasive Species Specialist Group (ISSG) based on the unified checklist of alien species in Belgium which was created by TrIAS in support of research and policy using an open and reproducible workflow. The species occurrence ...