["Business Strategy and the Environment, Volume 35, Issue 3, Page 3468-3483, March 2026. ", "\nABSTRACT\nThis study investigates how B Corp certification enables hybrid organisations to integrate competing institutional logics of market and social purpose. Through a two‐stage qualitative design combining cross‐sector interviews with B Corps and an in‐depth case study, with a total of 30 participants, we analyse how certification supports hybrid organisations in practice. Three mechanisms of logic integration are identified: blending commercial and social logics to craft synergistic value propositions, assimilating social concerns into core business operations and elaborating existing practices to embed sustainability. B Corp certification emerges as a mediating institutional infrastructure that legitimises hybridity through frameworks for continuous improvement, stakeholder accountability and community building, while simultaneously imposing operational demands. Findings underscore the importance of sophisticated tension management across decision‐making, resource allocation and performance evaluation. The study contributes by refining theory on hybrid organisations and reframing certification as an enabling–constraining scaffold that renders paradoxes manageable rather than resolvable.\n"]