The taxpayers in the lawsuits argued that ISS (municipal tax on services), but not ICMS, should apply to the licensing or the right to use software in case of use licensing. The STF minister responsible for the case, Minister Dias Toffoli, stated during the hearing that “the simple fact that the services for licensing and assigning the right to use a computer program are defined in Complementary Law No. 116/2003 as being subject to ISS, in theory, subjects values related to software exclusively to ISS, removing any possibility of ICMS taxation.”
Source: Deloitte