What is biometric categorisation?
Biometric categorisation is assigning natural persons to specific categories on the basis of their biometric data (AI Act, Article 3(40)). The red line: systems that categorise people to deduce or infer race, political opinions, trade union membership, religious or philosophical beliefs, sex life or sexual orientation are a prohibited practice under Article 5, applicable since 2 February 2025 — with a narrow carve-out for lawful labelling of datasets in law enforcement contexts.
Below the red line
- Categorisation by other sensitive-adjacent attributes (age, gender, health indicators) is generally high-risk under Annex III;
- Exposed persons must be notified under Article 50;
- Ancillary technical filtering (e.g. detecting a face to apply a filter) is not categorisation in this sense.
Why it matters
Ad-tech, retail analytics and camera-based products flirt with this definition more often than teams realise — an “audience insights” feature inferring demographics from faces sits directly on the boundary. In Türkiye, the same biometric inputs trigger KVKK’s special-category regime. Related: emotion recognition system, social scoring.