In the licensing of intellectual property rights, the licensee regularly pays the license fee in exchange for the grant of a usage right from the licensor. If the right is declared null and void ex post or if it never existed from the beginning, this constitutes a mere empty transfer. Even in this case, jurisprudence and literature assume a proper fulfillment of obligations due to the de facto preferential position of the licensee. The book builds on this point and examines the legality and appropriateness of this solution by considering both the German and English legal situations. The author concludes that the de facto preferential position does not constitute a consideration for the payment of license fees and advocates for a strict reversal of the transaction.