Through a critical comparison of the spatial management of street vending in Ciudad del Este, Paraguay and New York City, USA, we show how uncertainty enables the management of vending and urban space. By uncertainty, we mean a condition characterized by legal complexity and negotiable enforcement of laws and regulations. Putting New York and Ciudad del Este in dialogue, we demonstrate that these negotiated legalities are not limited to Southern urbanisms, nor are they remnants of unmodern social forms. We find similarities in how vendors experience and negotiate uncertainty, even as divergent mechanisms link uncertainty and inequality. By claiming streets as sites of work, vendors challenge dominant notions of global urbanism which conceive of sidewalks as sites of circulation, rather than livelihood. Especially in Ciudad del Este, vendors know the biases of law, and ground their claims to livelihood in ethics rather than legal compliance. Yet vendors’ claims can also reinscribe hierarchical relationships with frontline enforcers and reinforce exclusionary notions of rights based in productive citizenship. Understanding how uncertainty works as a logic of governing helps expose these unavoidable tensions and therefore to imagine and construct pathways toward more just urban economies.