Internationalisation policies introducing English as a lingua franca (ELF) have been initiated by the Taiwan Ministry of Education and executed from a top-down level without taking into consideration the competence and needs of administrative staff. This article begins by describing the ideology of ELF within the macro context of Taiwanese tertiary education and then takes one micro context as an example of how a learner-based communicative ELF-wise curriculum was co-developed and successfully implemented to provide university administrative staff (n = 20) with the ELF training needed to perform job functions. The quantitative and qualitative analysis centred on the teacher's reflection report and students' knowledge about the reality of their willingness and competence in speaking ELF gathered through an open- and closed-ended questionnaire. Data revealed in spite of the teacher's native speaker background, his teaching methods empowered students to become fully involved in the development of learning texts, learning material evaluation, and a lingua franca ideology of communication. Students' increased communicative competence and willingness to speak lingua franca English resulted in a reduction of 'language deficit' ideologies and increased second language security. This article offers insights into implementation actions for institutes facing similar difficulties in the internationalisation of higher education.