The term "communicative competence" captures the notion that the ability to use language in interaction requires not just control of linguistic form but also awareness of rules of use in different contexts (Hymes, 1972). Communicative competence is a slippery term: different actors in second language (L2) research, education, and assessment interpret the term in a variety of ways and use it for a range of purposes, perhaps particularly in the field of languages for specific purposes (LSP). This is unfortunate because it is a key concept in LSP, as in applied linguistics more generally. Communicative competence can be considered to be the target of second language acquisition, a main goal of second or foreign language teaching and learning, or the object language testers seek to measure via performance tests. In addition, current interpretations of communicative competence may be somewhat questionable adaptations of Hymes' concept, modified and often simplified to reflect current approaches in both formal and functional linguistics, and to respond to practical concerns in language teaching and testing. This paper seeks to re-examine communicative competence from three perspectives -- L2 research, teaching, and testing -- highlighting problems in terms of theory and practice with respect to LSP. Drawing on recent research on indigenous assessment criteria, the paper concludes with a revised model of communicative competence for LSP, offering a richer interpretation closer to the original concept and to current concerns in the field.