Tax sovereignty, traditionally understood as a state’s authority to impose taxes, has been increasingly challenged by globalization, resulting in the adaptation of domestic tax regulations under international influence. At present, the OECD and G20 play a significant role in shaping domestic tax policy through soft law frameworks that guide reform. This article analyzes the baseline standards of the BEPS initiative as tailored for developing countries and examines the associated enforcement challenges. It further highlights how states have adjusted their domestic tax structures to align with OECD/G20 guidelines, reinforced by continuous monitoring and peer review mechanisms. Since 2015, the BEPS initiative—particularly its four Minimum Standards—has been stringently enforced. Despite differing national interests and the complexities involved, the OECD’s peer-review process has steered national policy adjustments, fostering a shift toward a more unified global tax framework, which has, in turn, diminished national tax sovereignty. © Tambunan R.U.D. M., 2026.