Employees’ participation in professional international business (IB) communication has important consequences for knowledge transfer and processing, a crucial function for multinational enterprises (MNEs). Research suggests that participation is shaped by language, but prior research has focused on firm-internal language dynamics, meaning that less is known about the influence of external context. We help redress this balance by drawing on the sociolinguistic concept of “language ideologies”. Language ideologies, or shared sets of beliefs about language(s) amongst social groups, are societal-level phenomena that employees bring with them to work. As such, they are part of the external social, political and historical context of IB activities. Our analysis of 82 interviews in three countries indicates that some language ideologies block participation and create friction, while others support participation. Implications for the conceptual understanding of language in IB and the management of internationally active firms are discussed.