Plurilingualism, multimodality and interactional competence: talking about numbers in commercial interactions between Romance speakers. Grounding on a conversation analytic approach, this contribution explores how participants talk about prices and other exact numbers in commercial encounters between Romance speakers. Through a sequential and multimodal analysis of audiovisual data of naturally occurring interactions, this paper shows that, when speaking about numbers, participants use an especially large variety of practices to ensure intercomprehension: from gestures, to the mobilization of written materials, to the use of other languages. By doing so, they show creativity, flexibility and mindfulness about the particular context of communication. We argue that these plurilingual and multimodal practices can be seen as signs of a plurilingual interactional competence.