Abstract: The present study is based on the judgment of the General Court of the European Union in question, T 778/16 and T 892/16, which seeks the annulment of a sanctioning decision ordered by the European Commission in respect of State aid. The sanctioning decision is based on a tax agreement between the Apple groups of companies and Ireland. The technique of applying the tax law, through individual tax ruling is a common fact in the application of tax law, but raises two significant issues, which are the subject of this study: on the one hand the content of tax law to these acts and their legal significance, on the other hand, the effects generated, beyond the simple agreement on how to determine the tax, namely the generation of a favorable tax situation for a certain company through this unilateral. In relation to this effect, the combined cases allow a discussion on the diversion of the non-discriminatory nature to taxes and the generation of lighter tax hypotheses, equivalent to state aid. This legal regime can be analyzed through the filter of single market provisions.

Keywords: state aid; tax ruling; company taxation