ABSTRACT In 2022 at the UN climate conference in Sharm el-Sheikh (COP27), countries agreed to establish a new fund for loss and damage. This decision was one of the most significant outcomes of the COP, and something Small Island Developing States had spent the previous three decades calling for. The approach taken to realize this new funding arrangement includes many similarities to that taken to create a similarly significant new fund twelve years earlier – the Green Climate Fund (GCF) – including its design by a Transitional Committee. The aim of this article is to assess the extent to which the ambitions for the GCF have been realized, with a view to informing the ongoing design and early implementation of the new fund. To do this, the article compares the GCF’s present-day outcomes to its original intentions as described by the COP16 decision text. This paper finds that the GCF’s operation today only partially reflects the ambitions expressed at COP16. While the ambition for a Board with equal representation by developing and developed countries has been achieved, ambitions to expand the sources of finance and increase funding for adaptation have been mixed. The influence of the World Bank was a key point of tension over the GCF’s Transitional Committee period, and the Bank continues in the Trustee role today. The role of the Committee’s Technical Support Unit – the group of staff seconded from various international development banks and agencies to provide technical and administrative support to the GCF’s Transitional Committee – had an outsized influence on the shape of the GCF, such that these organizations continue to receive the bulk of GCF funding today. These findings suggest a greater plurality of voices providing such technical inputs would enhance the design of new funding bodies. The creation of new international finance institutions is relatively rare, so understanding the history of the GCF’s design is important for contextualising discussions about other climate finance options.