This paper outlines the key obligations across the policy cycle—development, implementation, reporting, and review— of national implementation plans (NIPs). This paper covers National Biodiversity Strategies and Action Plans (NBSAPs) under the Convention on Biological Diversity (CBD), as well as Nationally Determined Contributions (NDCs) and National Adaptation Plans (NAPs) under the Paris Agreement of the United Nations Framework Convention on Climate Change (UNFCCC). The aim is to identify opportunities to align policy cycles in order to improve the integrated development, implementation, reporting, and review of NIPs. This paper forms section 2 of the draft report “Advancing the biodiversity-climate nexus through MEAs - National implementation plans as catalysts for integrated action” prepared for UNEP.