[The retroactive period for supplementary tax on overseas income can go back as far as 2017] According to a report by Jinse Finance, it has been recently learned from multiple sources that the retroactive period for supplementary tax on overseas income for Chinese mainland tax residents has been extended compared to before, potentially going back as far as 2020 or even 2017. Since 2025, many tax residents have received reminders and notifications from tax authorities, requiring them to self-audit their domestic and overseas income and promptly file tax declarations. The retroactive scope for supplementary tax mainly covers the past three years, focusing on 2022 and 2023. (Yicai)