Authority is a key concept in politics and law, and it has found greater attention in the global context in recent years. Most accounts, however, employ a model of 'solid' authority borrowed from the domestic realm and focus primarily on commands issued by single institutions. This framing paper argues that such approaches tend to underestimate the extent of authority in global governance and misunderstand its nature, leading to skewed accounts of the emergence of authority and the challenges it poses. Building on an alternative conception – the deference model – the paper calls for including in analyses of global authority also liquid forms, characterized by a higher level of dynamism and typically driven by informality and institutional multiplicity. Such a broader account can help us to redirect empirical inquiries and reframe central questions about authority, relating in particular to the way in which it is produced, the mechanisms through which it might be made accountable and legitimate, and its relation to law.