Adopting the concept of a circular economy at a product level requires firms to rethink their business model and collaborate with partners across their value chain. Reaching product circularity through closing, slowing, and narrowing resource loops can be understood as a systems innovation, which calls for transdisciplinary research approaches. This paper presents insights from the ‘Innovation Network aiming at Sustainable Smartphones’ (INaS) located at the authors’ institute. INaS is a living lab that brings together actors from the entire smartphone value chain to co-create circular product and service innovations. We contribute to researchand practice with a process framework for leveraging partnerships through living labs for product circularity.