Corporations can significantly affect the fundamental rights of individuals. This book investigates how to determine the substantive content of their obligations that emanate from these rights. In doing so, it addresses important conceptual issues surrounding fundamental rights. From an investigation of existing legal models, a clear structural similarity surfaces in how courts make decisions about corporate obligations. The book seeks to systematise, justify and develop this emergent 'multi-factoral approach' through examining key factors for determining the substantive content of corporate obligations. The book defends the use of the proportionality test for ascertaining corporations' negative obligations and outlines a novel seven-step test for determining their positive obligations. The book finally proposes legal and institutional reforms - on both the national and international levels - designed to enhance the quality of decision-making surrounding corporate obligations, and embed fundamental rights within the corporate structure and the minds of key decision-makers.