Value added tax (VAT) is a key element of the tax system of Kazakhstan and the most important source of replenishment of the state budget. Its universal nature allows it to cover almost all sectors of the economy, influencing consumer demand, transparency of financial transactions and the investment climate. In the context of globalization and digitalization, the country's tax policy is undergoing constant reforms aimed at improving the efficiency of VAT administration, reducing the shadow economy and creating favorable business conditions. This paper examines the theoretical aspects of VAT, its evolution and the current state in the tax system of Kazakhstan. The analysis of the fiscal and regulatory functions of the tax has been carried out, the problems of administration and their impact on the economy have been identified. Special attention is paid to the impact of changes in tax legislation and digital control tools on the effectiveness of VAT collection. Based on the study, recommendations are proposed for improving the VAT collection mechanism aimed at increasing its fiscal efficiency, reducing the tax burden on entrepreneurs and increasing the transparency of the tax system. The hypothesis of the study is that proper VAT administration contributes to sustainable economic development, reducing the level of the shadow economy and improving the business climate in the country.