John Lewis has become the first UK retailer to implement AI-powered age checks for online knife sales with tech firm Yoti. The AI, trained on millions of facial images, estimates age with 1.3-year accuracy for people aged 13-17. This ensures that a higher age threshold is applied to prevent any under-18s from being mistakenly approved. Yoti claims the technology is already used on social media platforms and adult sites for age verification and has been approved by Ofcom under the Online Safety Act.