EU AI Act Article 50 takes effect 2 August 2026 and creates four distinct transparency obligations requiring different UX implementations: Article 50(1) chatbot interaction disclosure on providers, Article 50(2) machine-readable marking on generative AI output, Article 50(3) biometric categorisation and emotion recognition disclosure on deployers, and Article 50(4) deepfake disclosure on deployers (with the artistic-or-creative-work exception). The procurement-defensible disclosure UX has six properties (visible at the right moment, plain language, persistent or recurrent, linked to a substantive disclosure surface, auditable, updateable). Most enterprises have absorbed the legal text without designing the UX it requires.

Deadline-anchored claim pegged to 2 August 2026 enforcement window. Cadence 60-day with the first review immediately after enforcement opens (4 Aug 2026). Trigger conditions: AI Office detailed implementing guidance on Article 50 with named UX patterns endorsed or rejected; national supervisory authority enforcement actions in the first 12 months; industry-standards convergence on Article 50(2) marking for text-based generative AI. Sister claims: AM-046 (Article 12 audit substrate), AM-138 (post-enforcement MSA red-team), OPS-052 (NL solo legal Article 50 application).