Indonesia’s tax system is entering a new era. The Tax Directorate General Information System (SIDJP) will be replaced with the Core Tax Administration System (CTAS) or Sistem Inti Administrasi Perpajakan (SIAP). Currently, SIAP system is under the trial phase. The system is expected to make the taxation system more efficient and transparent as well as to extend the taxation to reach the informal sector which as of currently remains as unregistered tax subject.