The Personal Income Tax Act of 26 July 1991 provides for 50% tax deductible costs. This rule also applies to academic teachers. In this context, both the tax law regulations and the new regulations concerning higher education and science are of particular importance. In principle, the indicated legal areas should be coherent, especially that both the tax regulations and the provisions of the so-called Act 2.0 refer to copyright regulations. However, it is hard to resist the impression that the expected synchronisation has not been achieved in practice, which results in the creation of a specific legal dualism. It should be emphasised that the emerging interpretation difficulties were additionally highlighted by the general interpretation of the Minister of Finance. The prepared commentary to the judgment of the Supreme Administrative Court of 28 May 2021, II FSK 3717/18, only partially shares the substantive narrative of the Court, at the same time presenting the discrepancies in the presented argumentation and their negative consequences for the correct resolution of the problem and the practice of tax law.