BUM Desa Kencana Sari Amertha, a village-owned enterprise in Penglatan Village, Buleleng District, Buleleng Regency, Bali Province, is legally obligated to withhold, remit, and report Income Tax Article 21 (PPh 21) on honorariums and salaries paid to its management and workers. However, the recording of honorariums and salaries is still carried out manually without a standardized working paper, while management’s understanding of the Average Effective Rate (TER) scheme introduced by Government Regulation Number 58 of 2023 remains limited, creating a risk of calculation errors as well as delayed tax remittance and reporting. This community service activity aimed to develop and assist in the implementation of a Microsoft Excel-based PPh Article 21 calculation working paper to improve the tax compliance of BUM Desa managers. The implementation method consisted of five stages: preparation and a survey of existing conditions, development of the working paper comprising worksheets for permanent employees, non-employees/non-permanent workers, and a December reconciliation sheet, socialization and training, hands-on mentoring using real data, and evaluation through pre-tests and post-tests. The results show an improvement in the understanding of BUM Desa managers regarding current PPh Article 21 regulations and the TER scheme, as well as an increased ability to accurately and independently complete and use the working paper compared to before the activity. The resulting working paper is expected to be used on a sustainable basis as an instrument of administrative compliance and as part of the tax planning of BUM Desa Penglatan in the future.