As cities in the Global South gain visibility in global forums – engaging in climate negotiations, forming alliances and aligning with development goals – their legal and economic status remains structurally ambivalent. This article challenges the idea that these cities are becoming full international legal actors. Instead, we argue that they possess a ‘borderline international legal personality’: conditionally included in global regimes through mechanisms that reinforce long-standing asymmetries. Central to this dynamic is the notion of ‘creditworthiness’, now a key metric of development. Tools like sub-sovereign credit ratings pressure cities to prioritise investor confidence over local needs. These interventions promise international agency but often deepen financial dependency. We call for a re-reading of urban internationalism, attentive to the in-between status of Global South cities – caught between aspiration and discipline. Any emancipatory urban agenda must confront the financialisation of local governance and centre debt justice, autonomy and institutional reform.