Indebted cities were a widespread phenomenon during the Ancien Régime. However, some found ways to innovate the management of their municipal debt, whilst others fell prey to over-indebtedness or default. In this article we have left the success stories aside and focused on the latter. Using early modern Antwerp as a case study, we have disentangled the underlying mechanisms that ultimately lead to over-indebtedness and (in some cases) default. Whilst the economic climate and the relationship between city and state have been rightly identified as major factors in the previous literature, our contribution brings another element to the table, namely, the inflexibility of long-established rent arrangements and the entanglement between the ruling elite and the rentiers. We show that there was a strong overlap between both groups, which had a huge impact on the financial policy of cities during the early modern period.