Accounting for Nationally Determined Contributions (NDCs) under the Paris Agreement is needed to allow Parties to track individual progress towards their own mitigation-related NDC targets, understand others’ NDC targets and their progress toward them, and assess collective progress towards the long-term mitigation goal. This paper aims to assist Parties and stakeholders in framing thinking around the nature of accounting for mitigation targets given the diversity of target types in NDCs, and also to discuss how accounting guidance could be applied at various stages in the NDC cycle. It provides a summary and unpacking of the key accounting provisions under the Paris Agreement and Decision text, discusses the implications of the range of NDC target types, then discusses the particular issues of accounting for co-operative approaches and for the land sector. It then explores how accounting guidance may be applied within the NDC cycle.