The implementation of an English-only policy in an international class program (ICP) at Indonesian university poses unique challenges for non-native English-speaking teachers in ensuring student understanding. Translanguaging presents itself as a pedagogical alternative that allows for flexible use of language repertoires to support the learning process. This study aims to explore English lecturers’ beliefs about translanguaging, their practices in classroom interactions, and the factors influencing its implementation in the context of ICP at the university level. The study used a qualitative case study approach involving three lecturers who teach Listening, Grammar, and Writing in the second-semester ICP class of the English Language Education study program. Data were collected through classroom observations and semi-structured interviews, then analyzed using Braun & Clarke’s (2006) six-stage thematic analysis. The results show that: (1) All lecturers have positive beliefs about translanguaging as a necessary pedagogical strategy, not as a policy violation, (2) Translanguaging is applied spontaneously and responsively to clarify vocabulary, explain complex grammatical concepts, and check student understanding, (3) The main factors that influence translanguaging practices include students’ varying English language abilities, the level of difficulty of the material, and students’ non-verbal responses. These findings confirm that translanguaging is an organic pedagogical practice and needs to be formally recognized in the language policies of ICP programs in Indonesian higher education.