The Indonesia Climate Change Trust Fund (ICCTF) is the first national trust fund to seek funding from multiple donors to finance climate change policies and programmes. The ICCTF, which is anchored within the Indonesia Ministry for National Development Planning (Bappenas), aims to enhance national ownership and develop a structure to access and channel grants in response to climate change. As such, the ICCTF provides an innovative model for countries around the world seeking better access to international support for their climate change response strategies through nationally driven institutions. In practice, however, its operationalisation has been slow, and with a current capitalisation of $11.4 million, it is a relatively small source of finance in a country that accesses hundreds of millions of dollars of concessional donor support for climate related purposes. It is now one of many actors in an increasingly complex domestic climate finance landscape. An understanding of the context and evolution of the ICCTF offers important insights into the practical realities of establishing national climate funds. This working paper is one of a series of ODI studies which use a common analytical framework to examine the effectiveness of international climate funds. It will be revised to reflect feedback received and new developments.