[Yicai: The retroactive period for supplementary tax on overseas income can be traced back to as early as 2017] BlockBeats News, January 15, according to Yicai reports, it has recently been learned from multiple sources that the retroactive period for supplementary tax on overseas income for mainland Chinese tax residents has been extended compared to before, potentially going back to 2020 or even 2017. Since 2025, many tax residents have received reminders and notifications from tax authorities, requiring them to self-check 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.