The modernization of tax systems like Indonesia’s Core Tax Administration System (CTAS) offers potential benefits like increased efficiency and effectiveness. However, it also raises significant concerns about the protection of sensitive taxpayer information. This article explores these issues, analyzing the data protection laws in Indonesia, the possible dangers associated with gathering and handling taxpayer information in CTAS, and the strategies to reduce these risks. The article concludes that although CTAS offers numerous advantages, strong data protection measures, including clear regulations, robust security protocols, and transparency, are crucial to ensure taxpayer trust and the overall success of the system. In other words, While the Core Tax Administration System in Indonesia has great potential to optimize tax administration processes, resulting in improved efficiency and effectiveness.it is imperative to implement strong data protection measures alongside it to ensure taxpayer privacy is protected. This requires a comprehensive approach that includes clear regulations, strong security protocols, transparency, and accountability. By making the protection of taxpayer privacy a top priority, Indonesia has a chance to create a tax system that is trustworthy, efficient, and respectful of people’s basic rights.