This article draws on a study of language choice and language ideologies in an international company in Denmark. It focuses on the linguistic and social challenges that are related to the diversity of language competences among employees in the modern workplace. Research on multilingualism at work has shown that employees may be excluded from informal interactions and from access to power structures on the basis of language skills in the company's language(s). The data discussed here show that in the modern workplace, employees' linguistic competences are diverse; international employees often have competence in the company's lingua franca but lack skills in the local language while some 'local' employees lack competence in the corporate language (typically English). This can lead to the sociolinguistic exclusion of either group. In conclusion, the article relates these processes of exclusion to two language ideologies: one about an essential connection between language and nation and one about a hierarchy of English users.