The UK PREVENT programme aims to address radicalisation by identifying and supporting “at risk” individuals that are deemed vulnerable to extremism. Central to this process is the willingness of professional practitioners to report information to authorities, a duty consolidated through the Counter-Terrorism and Security Act 2015. Despite this, little is known about the thresholds to report from a policing perspective. How risk performs beyond fixed indictors which pre-figure terrorism is also underexplored. This qualitative study provides insight into PREVENT police officers’ accounts of the reporting stage of PREVENT. A thematic analysis of semi-structured interviews identified the mobilisation of intelligence on the basis of “gut feelings” and “instinct”. Professional partners in particular were encouraged to trust their own subjective judgements in the absence of observable risk indicators and tangible evidence. A simplified and relational risk logic was said to provide several operational benefits, for example, aligning the PREVENT team with non-specialist actors. To unpack the data theoretically, this article is inspired by the affective turn in human and social sciences and measures the data against the notion of “affect”. Finally, the findings are supported by an examination of national counter-terrorism policing campaigns, PREVENT briefing documents, and Home Office initiatives. The key propositions therefore have wider implications for policy and practice.