Navigating biocidal product authorisation pathways in the EU and Great Britain has become increasingly complex as regulatory divergence continues. This presentation offers a concise overview of the main registration routes under both the EU and GB Biocidal Products Regulation (BPR) – covering transitional (pre-BPR) approaches, National, Union and Simplified Authorisations, Mutual Recognition, and country-specific processes. We will highlight the advantages, limitations, and unexpected challenges associated with each route, illustrating where the two systems align, where they differ, and how these differences impact data requirements, timelines, costs, and strategy. Attendees will gain a clear understanding of how to choose the most appropriate pathway for their products, anticipate common obstacles, and prepare for emerging regulatory obligations, including new EU bees and drinking water treatment assessments.