This study focuses on the sectoral and geographical differences in open knowledge collaboration for the innovation performance of UK firms. Drawing on transaction cost theory and appropriability of knowledge, we adopt a resource-based view to focus on limits to open innovation. We use a generalized multi-level mixed model to test our hypotheses, controlling for time, regional and firm unobserved characteristics. Our sample includes 19,510 observations and 17,859 firms, with a small panel element of 1651 firms mainly from the UK Innovation Survey and Business Registry. Our results demonstrate that limits to open innovation differ across knowledge-intense sectors and at different geographic dimensions, with creative sectors experiencing the greatest limits to knowledge collaboration in both national and international markets. We discuss why and how this occurs, and conclude with several theoretical and policy implications.