In a most recent judgment, the Supreme Tax Court decided that the trade tax addback of a silent partner's profit share is subject to the free movement of capital which also applies to third countries (here: the USA). The application of the "grandfather“ clause of Art 64 TFEU (ex-Article 57 TEC) is generally not affected by statements made in a letter from a lower tax authority.
The European Court of Justice has held that the German provision for the taxation of controlled company income from invested capital from outside the EU might fall under the “grandfather” clause of Art 64 TFEU, provided the German legislation has remained substantially unchanged since that date. It is now for the Supreme Tax Court to decide finally whether this is the case.