This study investigates the imperative of modernizing tax systems, employing a comprehensive approach that combines theoretical exploration with empirical inquiry. The study unfolds against the backdrop of increasing global complexity and the pressing need for tax systems to adapt to evolving socio-economic landscapes. The overarching purpose of this research is to comprehensively explore tax system modernization by unraveling theoretical underpinnings, scrutinizing diverse modernization strategies, and critically evaluating the effectiveness of the Goods and Services Tax (GST) model as a contemporary taxation framework. The methodology integrates a meticulous literature review synthesizing key theories and empirical evidence with an in-depth analysis of the GST model's implementation and impact. coverage of various disciplines such as economics, accounting and Finance, public policy, and taxation. The findings reveal a wealth of empirical evidence supporting the effectiveness of Goods and services tax as a contemporary effort of the modern tax system. This study's significance lies in its contribution to the discourse on tax policy and administration, offering actionable insights for policymakers, economists, and stakeholders navigating the complexities of modern tax systems