A strong vision of sustainable development requires respect for the limits imposed by the functioning of the planet to ensure its resilience. The framework of planetary boundaries is increasingly relied on to design quantifiable objectives that can guide policy- and decisionmakers to enact measures to ensure such a sustainable society. Yet, to effectively guide, the framework requires a reformulation to make it applicable to human activities. Concretely, planetary boundaries need to be transposed into planetary quotas, which express the maximum absolute quantity of emissions, withdrawals or use that is admissible so as not to exceed the planetary limits. Furthermore, the achievement of planetary quotas depends on the fair allocation of national, sectoral, or even individual quotas. In this context, we question whether and under which institutional conditions environmental quotas could be an appropriate tool to implement planetary boundaries. This article proposes a legal and political theory of quota systems and applies it to the establishment of planetary quota systems in international environmental law.