Implementasi Sistem Coretax dalam Pembuatan e-Bupot dan Pelaporan Surat Pemberitahuan (SPT) Masa PPh 21 Pada PT RSA

This study examines the implementation of the Coretax system in preparing electronic withholding tax slips (e-Bupot) and submitting Monthly Income Tax Article 21 (PPh 21) Returns at PT RSA. Coretax, launched by the Directorate General of Taxes (DGT) and officially implemented on January 1, 2025, is part of the government’s effort to modernize tax administration and improve taxpayer compliance. The research uses a qualitative descriptive method with a case study approach. Data were obtained through interviews with personnel responsible for PPh 21 administration, direct observation of e-Bupot preparation and monthly tax return filing through Coretax, and documentation review of tax reports and withholding slips. The analysis compares PT RSA’s practices with applicable tax regulations and identifies technical challenges during system use. The results show that PT RSA has complied with prevailing regulations, including the application of the Average Effective Rate (TER) and the utilization of Coretax for tax administration. However, technical constraints remain, particularly unstable internet connections and slow Coretax server performance during peak reporting periods, leading to data entry delays and upload failures. Therefore, improvements in system stability and performance are needed to support timely reporting and optimal tax compliance.