The main challenge for a sustainability transition is to scale up successful solutions. Upscaling requires coalitions of public, private, and civil society actors who align their motivations. Pathways to upscaling may involve leveraging a dominant player's market power, integrating successful initiatives into public policy, or reinforcing government-led change with private efforts. Various actors agree to collaborate to take advantage of their complementary capabilities, e.g., government policies facilitate private action, market incentives reward progressive actors while government sanctions punish laggards, actors take up different tasks of the policy cycle, and large players absorb and disseminate pioneer efforts. To achieve durable impacts, the upscaling of solutions to reach sustainability must continually maintain a balance of incentives among key actors. The paper identifies general lessons for successful upscaling that provide insights on the importance of motivating actors, designing collaborations for lasting success, and incorporating concerns of developing countries.