Disclosing Scope 3 GHG emissions beyond an aggregate emissions figure is essential for enhancing the transparency of, and accountability for, Scope 3 GHG emissions reduction – accounting for between 80% to 95% of total GHG emissions in many sectors. We assess the informativeness of Scope 3 emissions disclosures by listed companies in Australia and New Zealand between 2020 and 2023 preceding the mandatory disclosure regime. We find that it remains a minority practice with 7.4% (43.8%) of Australian (New Zealand) listed companies voluntarily disclosing Scope 3 emissions. On closer examination of those making disclosures (518 firm-year observations and 829 corporate reports), we document an overall low (albeit increasing) level of disclosures, which varies significantly across companies, questioning the informativeness of Scope 3 emissions disclosures. However, we also find evidence that the informativeness of Scope 3 emissions can be improved through accumulated disclosure experience, following an internationally recognized reporting framework, and engaging in third-party assurance. Additionally, companies tend to make more informative Scope 3 emissions disclosures when Scope 3 emissions are more material. Finally, firms in New Zealand generally produce more informative Scope 3 emissions disclosures than firms in Australia, likely driven by the earlier regulatory move on this front.