At the beginning of 2016, the so-called "research and development relief" (hereinafter: R&D relief) was introduced to the Personal Income Tax Act and the Corporate Income Tax Act. The mechanism of the relief lies in the possibility to deduct from taxable income expense specified in the Act (so-called "eligible costs") incurred by the taxpayer for research and development, despite the fact that the expense has already been recognized as tax deductible.