The article clarifies the content and relationship between the concepts of «tax optimization» and «tax planning». The criteria for distinguishing these concepts are determined. It is established that tax planning is a multistage process which includes both strategic forecasting and careful organization of tax liabilities at each level of business. The main goal of this process is to be able to shape the structure and form of the business in such a way that they are optimal from the taxation point of view. Tax planning primarily determines the choice of a business entity’s strategy. Tax planning is defined as an important element of a company’s strategic management aimed at long-term and comprehensive management of tax liabilities. Tax optimization is an important process aimed at adapting the taxpayer to the peculiarities of the current tax system in order to choose the most profitable and efficient taxation regime. This process is not limited to the passive application of tax rules, but involves the active management of tax liabilities within the limits of legally permissible techniques, means and methods. Tax optimization is not only the ability to choose the most favorable conditions from those offered by the legislator, but also the ability to predict and adapt to changes that may affect the tax burden in the future. Tax optimization as a legal tool for reducing the total tax burden is considered exclusively within the framework of legal actions of the taxpayer. A distinctive feature of tax optimization as compared to tax planning is its focus on achieving short- and medium-term goals of a business entity by directly using the opportunities provided by tax legislation. Tax planning, on the other hand, is an element of strategic management aimed at achieving the long-term strategic goals of a business entity. Tax optimization is aimed at developing the most favorable model for fulfilling tax obligations by a business entity without changing the economic substance of business transactions. This approach allows the taxpayer to flexibly adapt to changes in the tax environment, while maintaining the sustainability of financial results and reducing tax costs. Tax optimization is not just a tool for reducing the tax burden, but also an important element of tax planning.