It is well-established that the banking sector has a particularly effective private lobby, both at the national, regional and global level. The Institute for International Finance is one of the key institutions in this lobby representing over 400 internationally active financial institutions. From its origins as an information sharing-point for banks which was egged on by the IMF and other prominent public policymakers, the IIF has developed into the key interlocutor for the Basel Committee on Banking Supervision. Given its central role in the political economy of bank reform, surprisingly little literature focuses on the development and role of the IIF (but see McKeen-Edwards & Porter 2013). This paper aims to fill that void by drawing on a unique set of interviews with IIF and other policymakers (three waves of interviews conducted between 1990 and 2008) and archive sources. Specifically, it will examine the interaction between changing market structures, shifting patterns of governance and changes in the IIF’s structure and lobbying behavior. This way, the paper will contribute to the unpacking of the private sector lobby with respect to banking regulation and contribute to a better understanding of the mechanisms through which banks influence global financial governance.