Sustainability transitions are purposeful and require deliberate collective action from multiple organizations, leading to the necessity to adopt new business models and redesign value networks. In both business model and sustainability transition research, the explicit activities needed to re-shape value creation and capture systems of organizations are largely unaddressed. We aim to fill this gap by proposing collaborative sustainable business modeling (CSBMing) as a participative multi-actor approach aimed at value network innovation to accelerate sustainability transitions. To do this, we first conceptualize a sustainability transition as a business ecosystem change. We then introduce the value network as the interceding level connecting the individual business to the wider ecosystem, which upon scaling, can change the ecosystem, leading to transition. CSBMing aims to redesign value networks and may thus be used as an actionable approach to accelerate transitions. Second, through the multi-level perspective, we explain how CSBMing can scale, influence other value networks, and change the ecosystem. Third, we recognize that scaling value networks might need more than just implementation of a CSBM and show how elements of CSBMing can complement executing transition management activities. We illustrate the potential role of CSBMing in accelerating transitions through two examples from the Dutch energy transition. In all, we show that CSBMing can be a fruitful approach to innovate and scale value networks, create collective action needed for sustainability transitions, and contribute to transition management activities.