In order to reform fossil fuel subsidies, G-20 governments must first identify the scope, value and impacts of the subsidies they provide to both fossil fuel producers and consumers. Standardized and regular reporting on subsidies is a crucial first step and should be complemented with an international monitoring framework. The Global Subsidies Initiative (GSI) has developed tools for identifying, classifying and quantifying fossil fuel subsidies. The GSI also has research underway to explore how reporting and transparency can be improved at national and international levels, including looking at options for developing an international governance framework for fossil-fuel subsidies. In preparing their implementation plans, G-20 governments will also need to develop clear objectives and timeframes, coherent policy packages that include measures to cushion any negative effects of subsidy reform, communications strategies coupled with extensive stakeholder consultation and a process for peer review of progress towards reform. The policy brief outlines the GSI's initial thinking on these issues in response to the G-20 communiqué.