The European Commission’s Mission for “100 Climate-neutral and Smart Cities by 2030” (“the Cities Mission”) seeks to accelerate Europe’s climate action commitments as part of the European Green Deal, whose ambition is to make Europe the first climate-neutral continent by 2050. The Cities Mission’s central tenet is to elevate and deepen the commitment to pursue systemic change through research and innovation, setting an ambition for cities of unprecedented scope and scale. In order to achieve such effects, a demand-driven Mission Platform has been established to provide tailored assistance and services to participating cities and those learning from them. As a part of the Horizon 2020 Work Programme, Building a low-carbon, climate resilient future: Green Deal call, the “LC-GD- 1-2-2020: Towards Climate-Neutral and Socially Innovative Cities” topic selected the four-year project NetZeroCities to establish the Mission Platform, which began work at the same time as the formal establishment of the Cities Mission, in October 2021. The scope of work presented herein will comprise the second Specific Grant Agreement (SGA2-NZC) development under the Framework Partnership Agreement FPA-NZC for the Mission Platform to scale and continue operations through 2027. Activities primarily focus on two objectives: the first to reinforce the support received by cities selected to participate in the Mission on financing their roadmap of activities towards climate neutrality, and the second to develop basic Mission Platform services for cities who are willing to commit to climate neutrality on a longer timescale than the Cities Mission.