This book presents papers from the 12th Cambridge Workshop on Universal Access and Assistive Technology (CWUAAT 2025), to be held in April 2025. This workshop series has hosted the multifaceted dialogue on design for inclusion since 2002, involving disciplines including design, computer science, engineering, architecture, ergonomics and human factors, policy and gerontology. The conference theme for 2025 is New frontiers for inclusion. The major themes dealt with in this collection include: Understanding people Designing for an ageing population Designing for particular needs Designing inclusive environments New challenges and opportunities the possibilities and challenges for inclusive design offered by AI and other emerging technologies. With its thematic wealth, this proceedings provides a unique insight into the current national and international research in the fields of inclusive design, universal access, and assistive and rehabilitative technology.