Code-switching is common in multilingual EFL classrooms, yet its structural types and pedagogical functions in Indonesian vocational high schools remain underexplored. This study aimed to identify the types of code-switching used by teachers and students in vocational EFL classroom interactions and examine their communicative and pedagogical purposes. Employing a qualitative descriptive design with a discourse-oriented approach, the study was conducted at a vocational high school in Southeast Sulawesi, Indonesia. Data were collected through classroom observations, field notes, and semi-structured interviews with two EFL teachers and ten students. The data were analyzed using Poplack’s (1980) typology and triangulated with interview and field-note data to enhance credibility. The findings identified 29 instances of code-switching: inter-sentential switching (69%), intra-sentential switching (17%), and tag switching (14%). Inter-sentential switching predominated and primarily supported idea negotiation, argument development, and instructional scaffolding. Tag switching reflected sociocultural values of politeness and respect toward teachers. These findings indicate that code-switching functions as a purposeful multilingual pedagogical resource rather than a linguistic deficit. Principled and context-sensitive language alternation can support comprehension, interaction, and English learning objectives in vocational EFL classrooms.