Interpreters may see affinities between their own or working language(s) and others in the same family as an opening to a broader range of professional opportunities. This paper presents data from an online survey, completed by 23 mainly Australian-based interpreters for the Bosnian, Croatian and Serbian languages. Main points include: number of accreditations (one, two or three languages); willingness to work in languages other than one’s ‘own’; and views on adapting language to the variety spoken by interlocutors (in both everyday usage and interpreted speech). Other questions examine negotiation of mismatches between ethnicity and the language variety expected by the client, as well as personal views regarding the distinctness of the three languages. Informants form three main groups: some work in one language only, with no accommodation to others; some consider the languages as separate but might accommodate to other varieties, extemporaneously or by prior arrangement; others consider that their native-speaker status in two or three languages makes accommodation superfluous. Two smaller groups (totalling four interpreters) consider substantial accommodation unnecessary: in one case they see the languages as separate but mutually understandable, in the other they see them as one single language. Quantitative data are complemented by informants’ comments.