Throughout Europe we observe a significant trend of increasing state intervention in the governance of religious practices and expressions. A growing number of policies and procedures seek to define and regulate how religion can, and cannot, be expressed in the public domain. In this article we explore how ideas of ‘good’ and ‘bad’ religion are translated into policies in urban contexts. We disentangle the social imaginaries that underlie the symbolic boundaries that distinguish between ‘acceptable’ and ‘unacceptable’ expressions of religiosity, and the repertoires of justification used to enforce them. Drawing on empirical research in cities in France and Spain, we argue that public expressions of religion are more likely to be deemed ‘acceptable’ in public as long as they meet a series of criteria, namely being perceived as: a) aesthetic and festive, rather than outrageous, b) discrete/decent/decorous rather than interpellating and, more importantly, c) exceptional rather than ordinary, d) freely chosen rather than imposed, e) cultural rather than pious, f) being legible with existing reference frameworks and categories rather than unintelligible. In other words, religious expressions are accepted, and considered to be acceptable, if they ‘fit’ or can be made ‘fit’ certain social expectations.