As part of the 2020 tax reform, Switzerland introduced a mandatory patent box as well as an optional R&D super deduction at the cantonal level. The patent box applies to the cantonal tax liability and allows a maximum exemption of 90% of qualifying income from cantonal level taxation. The rate of exemption varies by canton and is subject to mandatory general limitation rules of tax relief that cap the amount of relief firms can obtain from the use of tax instruments at the cantonal level. This cap also varies by canton. The rates displayed represent the combined effective tax rate applicable in case of maximum relief at the cantonal level accounting for federal tax liabilities for an investment in the canton of Zurich and include the effect of the patent box, the R&amp;D super deduction and the cap on tax relief. The applicable rate under the schemes varies between 9.1% and 13.9% while the rate that would otherwise apply varies between 11.9% and 21.6% among cantons.