Guided by the framework of internationalization at home (IaH), this study employed a mixed-methods approach investigating the development of intercultural communicative competence (ICC) among a group of tertiary English as a Foreign Language (EFL) learners in Taiwan, facilitated through the means of telecollaboration. The telecollaboration incorporated 30 EFL learners and 30 learners of Chinese from Australia and New Zealand. Data collection encompassed EFL learners' responses to a self-assessment questionnaire, their reflective essays, alongside instructors' reflective journals. The findings showed that EFL learners held positive perceptions regarding their telecollaboration experience and reported substantial growth in ICC across three dimensions: cognitive, affective and behavioral. In applying various multimodal communication strategies, EFL learners realized and valued cultural similarities and differences. Their reflective accounts exhibited evidence of enhanced linguistic and cultural competences. The telecollaboration enabled them to increase their confidence in utilizing English, hone their digital literacy skills for effective communications, and establish conducive environments for their relational and emotional development with their teammates and instructors. The latter provided indispensable emotion in varying contingent situations. Incorporating the insights drawn from the instructors' reflective journals, the study argues that telecollaboration as a pedagogical practice is the significant essence of effective IaH curriculum design and implementation.