Technological developments have triggered an increased use of profiling in a wide range of contexts, and using profiling tools to support the work of law enforcement and border management officials has recently received greater attention from EU Member States. Profiling is legitimately used to prevent, investigate and prosecute criminal offences, as well as to prevent and detect irregular immigration. But unlawful profiling can undermine trust in the authorities and stigmatise certain communities. This guide explains what profiling is, the legal frameworks that regulate it, and why conducting... profiling lawfully is both necessary to comply with fundamental rights and crucial for effective policing and border management. The guide also provides practical guidance on how to avoid unlawful profiling in police and border management operations.