The identification and tracking of climate-related forest expenditure in national budgetary systems has the potential to aid policy development, planning and financial resource management. Increasing both transparency and accountability of these flows will allow for monitoring and evaluation of spending, help determine if national policy targets are being met and if resources are being spent properly. However, identifying what counts and how to count climate-related forest expenditure is complex. Indeed, to date, there is no single definition of climate-related forest expenditure. This paper consolidates the issues and existing approaches to defining climate-related forest activities and finance. Integrating the multiple approaches, six categories of climate-related forest activities are identified. A step-wise tool is then proposed that allows the identification of budgetary expenditure within these categories.