Beyond Digitalization: Understanding Taxpayer Adaptation, Compliance Costs, and Voluntary Compliance in Indonesia’s Coretax Reform

Indonesia’s implementation of the Core Tax Administration System (Coretax) represents a major shift toward integrated digital tax administration. This study examines how taxpayers and tax professionals adapt to Coretax, how the transition reshapes compliance costs, and how these experiences relate to voluntary tax compliance. A qualitative case study approach was employed involving 100 participants from Jakarta, Bandung, Surabaya, and Malang, including corporate taxpayers, tax and accounting staff, tax consultants, tax practitioners, academics, and tax administration officials. Data were collected through semi-structured interviews and analyzed using reflexive thematic analysis. The findings reveal that Coretax implementation is experienced not merely as technological change, but as an administrative transformation requiring procedural relearning, internal workflow adjustment, cross-functional coordination, and the development of new administrative capabilities. Six dimensions of compliance costs emerged: learning, time, monetary, organizational, technological, and psychological costs. These burdens were most pronounced during the early transition period, although some declined as users developed familiarity and administrative routines. The findings further show that digitalization alone does not automatically strengthen voluntary compliance. Participants associated willingness to comply more closely with procedural clarity, system reliability, accessible support, and trust in tax administration. The study contributes to digital tax administration literature by integrating taxpayer adaptation, administrative burden, compliance costs, and voluntary compliance within a single qualitative framework. Practically, it highlights the importance of user-centered implementation strategies that reduce transition burdens while strengthening taxpayers’ confidence in digital tax administration.