This paper introduces the principles of a unifiedlanguage devoted to the area of competence-based enterprisemodelling. The language, named UECML, for UnifiedEnterpriseCompetenceModellingLanguage, is intended to provide a neutral interface to enterprisemodelling based on competences. Therefore, it is built on previous languages, especially UnifiedEnterpriseModellingLanguage (UEML) and provides constructs to cover process, resource, competence and enterprise entities. An example of the implementation of the proposed UECML is provided with its application to a producer of railway vehicles.