In this article, the classification of underground space types is analyzed. It is established that there are objects that are taxed in the tax code of Ukraine and there are those that are not taxed. The results of the research are justified by the lack of mechanisms and technical solutions of three-dimensional objects of commercial space taxation, which have been intensively developing in Ukraine. The ways of solving legal conflicts regarding registration and taxation of real estate objects are suggested. Based on the study of the legislative base and normative legal documents in the sphere of land relations, a classifier of three-dimensional space objects, which today are fully or partially used for commercial purposes in various types of economic activity has been proposed. The analysis of the regulatory and legal framework regarding the taxation of underground space facilities has been carried out. Objects for which the taxation of land is charged and those objects for which there is no charge for the use of underground space have been identified. A methodology for the justified calculation of a decreasing percentage ratio for calculating a normative monetary evaluation (NME) is developed for the cases where the object of an underground commercial space is located at a distance from the center in one of the proposed zones.