An NDC may be adjusted at any time, so long as the adjustment enhances its level of ambition. The INDCs that have already been submitted by Parties will become NDCs once the Parties concerned join the Paris Agreement. By 2020, Parties with INDCs for 2025 are to communicate new NDCs, and Parties with INDCs for 2030 are to communicate or update their contributions. Common timeframes for NDCs are to be considered at the first session of the CMA 1.