This paper analyses unauthorised turns – namely, interruptions – in parliamentary debates, by focusing on their lesser-studied interactional characteristics, that is, reactions. Drawing upon cross-cultural pragmatics, we compare reactions in Finnish (Eduskunta of Finland), French (Assemblée nationale of France) and German (Bundestag of Germany) parliamentary debates. In doing so, we applied conversation analysis in the sequential analysis of reactions to interruptions while considering restrictions related to written transcriptions. While most interruptions passed without reaction in all three languages, the reactions came from different sources: from unauthorised speakers in French, from authorised speakers in German and from both in Finnish. Our study demonstrates that interruptions serve as resources for micro-interactions within official speaking turns in parliamentary debates, revealing cross-cultural differences in speech styles.