UK Online Safety Act: Ofcom publishes final illegal content enforcement guidance

Ofcom has published its final guidance on how platforms must comply with illegal content duties under the Online Safety Act, setting out enforcement expectations for the detection and removal of child sexual exploitation and abuse material, including AI-generated CSAM. The regulator specifies that platforms must use proactive technology to identify illegal content, maintain systems to prevent children from encountering harmful material in private messaging, and report CSAM to the National Crime Agency. The guidance takes effect in December 2026 and applies to all user-to-user services and search engines operating in the UK.

Meeting proactive detection obligations in private messaging channels requires technology that can assess risk without compromising end-to-end encryption or subjecting every user to blanket content scanning. As a Meta Business Partner, Guardii delivers pattern-based detection across direct messages on major platforms, flagging grooming, sextortion and CSAM including synthetic and deepfake imagery by analyzing conversational dynamics rather than reading message contents, so that hostile contact is blocked or escalated before a child is harmed. This approach enables platforms to satisfy their duty to prevent illegal contact reaching minors while preserving user privacy and avoiding the operational burden of manual moderation at scale.