Clearing forms the core part of a smooth and efficiently functioning financial market infrastructure. Traditionally, it has been provided by clearing houses, most of which today act as a 'central counterparty' (CCP) between the two sides of a trade. The rapid growth of cross-border trading has sparked discussion on the most efficient industry structure - particularly in Europe and the US. At the heart of this discussion lies the question of whether the implementation of a single clearing house creates greater benefits than a more competitive but interlinked market structure. This is the starting point for this book, which analyses the efficiency of clearing and clearing industry structure. Along with clear-cut definitions and a concise characterisation and descriptive analysis of the clearing industry, the book determines the efficiency impact of various cross-border integration and harmonisation initiatives between CCPs. This serves to identify the most preferable future structure for the clearing industry.