An updated list is presented of the alien species in the transport or introduction invasion stage in inland waters of the Iberian Peninsula. The list is based on a systematic assessment of information in collaboration with a wide expert team from Spain and Portugal. This list is an important tool to support the implementation of the IAS Regulation, particularly in prevention measures and in the development of an Early Warning and Rapid Response (EWRR) system. Ultimately, the information included can help to the achievement of the target of the EU Biodiversity Strategy to 2030 for combatting IAS, but also for the implementation of other EU policies with requirements on alien species, such as the Birds and Habitats Directives, the Marine Strategy and Water Framework Directives.