Critical materials (CMs) are key to UK manufacturing, including for the aerospace, automotive, energy and chemical sectors, which rely on materials typically extracted and processed abroad. CMs are vital components of several emerging technologies, including electric vehicles, renewable energy infrastructure such as wind turbines, and digital technologies such as computers and smartphones. The UK imports most of its CMs and faces international competition for key resources. This POSTnote looks at the demand and supply of CMs in the UK and ways of improving supply security.