TUST e TUSD: funcionamento dos sistemas de transmissão e distribuição de energia elétrica e a (im)possibilidade da inclusão de suas tarifas de uso na base de cálculos do ICMS

Abstract

The tariffs for the use of transmission and distribution systems of electricity are amounts paid for the maintenance and operation of the mechanisms that enable the transport of energy from the generators to the final consumer. However, their legal treatment has been a significant source of controversy, particularly regarding their relationship with ICMS. Due to the unique characteristics of the electricity trade, a complex process that is divided into different stages until it reaches the consumer unit, there is no consensus on what should constitute the “operation” on which ICMS - electricity should be levied. Doctrine and the most current legislation, particularly Complementary Law 87/1996 (amended by Complementary Law 194/2022), understand that the tariffs for the use of the transmission system (TUST) and distribution system (TUSD) should not be included in the ICMS calculation basis. The courts held this view as well until the Superior Court of Justice introduced a new interpretation in the judgment of REsp 1.163.020/RS, arguing that the interdependence inherent to the electricity trade allows TUST and TUSD to be included in the tax base. This work aims to examine the electricity commercialization process in light of applicable doctrine and legislation and to discuss whether the recent decisions rendered by the STJ align with the in-depth study of the subject. The methodology employed in the development of this work is descriptive-analytical, based on bibliographical, documentary, and jurisprudential research, encompassing both tax law scholars and engineering experts connected to the electricity sector, as well as documents from governmental bodies and decisions from higher courts. Initially, the work delves into the study of the matrix rule of tax incidence and its relationship with ICMS. Subsequently, it addresses the functioning of the electric sector in the country and the complexity of ICMS - electricity. Finally, it analyzes the recent decisions of the higher courts in light of the discussions in the previous chapters and reflects on whether the interpretation formulated by the Superior Court of Justice is the best solution to the issue.