This paper makes a contribution to the study of impoliteness. More particularly, it explores conventionalised impoliteness formulae and their basis. It taps into debates about whether impoliteness (or politeness, for that matter) can be inherent in expressions, and argues that there is a sense in which it can. An important foundation for this paper is Terkourafi's (e.g. 2001, 2002) work on formulaic politeness expressions. However, it argues that Terkourafi's strong focus on the frequency of people's direct experience of linguistic expressions in specific contexts, whilst appropriate for politeness, does not entirely suit an account of conventionalised impoliteness formulae. Indirect experience of impoliteness, especially via metadiscourse, does much to shape what counts as impolite and thus what may be conventionalised as impolite. Such impoliteness metadiscourse is driven not only by the salience of impoliteness, but by the social dynamics of impoliteness itself. Finally, this paper proposes two methods for identifying conventionalised impoliteness formulae (one being akin to Terkourafi's method), and offers a preliminary list of such formulae in English.