We examine the impact of an exogenous shock that mandates disclosure of subsidiary tax residence locations. Since 1 July 2023, Australian public companies must disclose the tax residency of all subsidiaries, regardless of their materiality, in a ‘consolidated entity disclosure statement’ (CEDS) within the annual report. This new mandatory disclosure requirement aims to increase transparency and reduce tax avoidance, with the level of disclosure required going beyond existing subsidiary disclosure requirements in comparable countries such as the United Kingdom (UK) and the United States (US). Visibility of tax structures may attract public scrutiny and harm a firm’s reputation, which may lead to a firm strategically adjusting its corporate structure or tax affairs to placate external stakeholders. Consequently, we exploit the swift introduction of this new disclosure requirement to study its real effects. First, we document the extent to which firms operate in tax havens. Next, we investigate whether the new CEDS disclosure induces firms to decrease their use of tax haven subsidiaries and reduce their level of tax avoidance. Overall, we find some evidence of a decrease in tax avoidance but no evidence of a decrease in the use of tax havens, consistent with increased tax transparency not being a panacea. Our findings inform regulators and policy makers interested in the efficacy of the CEDS requirement and tax transparency generally.