The Open Budget Survey 2017, released in January 2018, assesses and compares budget transparency, oversight and participation in countries around the globe. Countries are ranked in the Open Budget Index (OBI) using their transparency score from the Survey. We previously provided a brief overview of the Survey including Australian findings and recommendations. This Policy Brief explains the OBI in more detail and discusses the state of budget transparency, participation and oversight in Australia, regionally and globally. We identify some gaps in the Australian budget system and conclude with lessons to be learned from the Survey for Australia and the region.