Discussions of political obligation and authority have focused on the idea that the commands of genuine authorities constitute content-independent reasons. Despite its centrality in these debates, the notion of “content-independence” is unclear and controversial, with some claiming that it is incoherent, useless, or irrelevant. I clarify content-independence by focusing on how reasons can depend on features of their container. I then show how the fact that laws can constitute content-independent reasons is consistent with the fact that some laws must fail to bind due to their egregiously unjust content. Finally, I defend my understanding against challenges and show why it retains a place of special importance for questions about the law and political obligation. Content-independence highlights that it is some feature of the law or law-making process in general that is supposed to generate moral obligations for citizens, not the merits of particular laws.