The book addresses the question of whether and how internationally active companies can claim foreign losses in their domestic taxation. The focus of the legal discussion is on the development of case law by the European Court of Justice (ECJ) since the Marks & Spencer case. With the increasing number of court decisions, cross-border loss offsetting in the context of final losses has become the subject of intense and controversial legal debate. This work provides a critical assessment of national tax law. The author examines the implications of the ECJ's rulings and explores potential solutions that could pave the way to fulfill the European idea of a common internal market.