PROJECT BACKGROUND Bat monitoring projects started in mid-20th century as a response to an increase in biodiversity loss generalised concern and have been dramatically evolving since then due to technological advances, methodological improvements and the upsurge of citizen science. The acknowledgement of bats as good candidates as bioindicators and the recognition of all the threads they face has fostered a more widespread international collaboration and coordination. The establishment of the Agreement on the Conservation of Populations of European Bats (EUROBATS) in 1991 represents a key milestone for bat conservation and an inflexion point in the collaborative efforts and strategies for bat conservation across European countries. As a result of the work carried out by the Intersessional Working Group Monitoring and Indicators during the last few years, we have compiled all Bat Monitoring protocols' specificities and settings that have been applied across European countries in a single active and updatable repository. The standardisation of bat monitoring protocols across Europe is critical in order to generate comparable data to adapt and establish efficient conservation law. In the framework of the EUROBATS, harmonised monitoring practices will most probably aid in assessing bat population trends at both national and transboundary levels. International coordination is critical due to the presence of migratory species being affected simultaneously in diverse territories, as well as shared threats and policies affecting all species. By integrating data from a broad diversity of regions, the reliability of analyses and the development of optimised conservation strategies will improve substantially. On the other side, whether this harmonisation is not implemented, divergent monitoring approaches will produce incompatible datasets, hindering their utility in broad-scale assessments. A standardised monitoring framework will foster transboundary collaboration, capacity-building and the exchange of best practices and knowledge. Developing countries with limited financial resources will, more likely, be able to contribute to some extent to a shared knowledge base. Our initiative aligns well with general biodiversity conservation duties, especially those under the Convention on Biological Diversity and the EU Habitats Directive. Standardised data collection protocols will aid in the assessment of conservation actions on the ground, conservation initiatives, and mitigation projects, as well as the detection of emerging threats or the implementation of a wide variety of management strategies. In an era of accelerating environmental change, an integrated pan-european monitoring programme is essential for ensuring the long-term monitoring and conservation of bat populations. OBJECTIVES The primary objective of this dataset initiative was to compile and summarise all available information (including general settings, schedules and other particular specificities) on bat monitoring protocols and programmes being implemented across the EUROBATS Parties and Range States in order to make this information publicly accessible and dynamically updatable. This work was conducted with the support of the Intersessional Working Group on Monitoring and Indicators, in collaboration with the EUROBATS Advisory Committee and external collaborators. The resulting dataset will act as a living resource that will be continuously updated and refined as new methodologies are continuously developed. By ensuring transparency, accessibility, and long-term adaptability, we see this dataset publication as the foundation for the near future coordinated bat conservation efforts across Europe. IF YOUR MONITORING PROJECT OR PROTOCOL IS NOT INCLUDED IN THE DATABASE YET, PLEASE CONTACT THE AUTHORS IN ORDER TO INCLUDE IT IN THE UPCOMING VERSION.