A As a taxable entrepreneur (pkp), pt abc is obligated to issue tax invoices for everydelivery of taxable goods (bkp) or taxable services (jkp), including advance paymentsfor which tax invoices are issued using code 040 through the coretax administrativesystem. in order to support the implementation of this system in the issuance of tax invoices,the government has enacted regulations governing tax invoice issuance through theregulation of the director general of taxes number per-11/pj/2025 and the regulation ofthe minister of finance number 131 of 2024. under these regulations, the issuance ofadvance payment tax invoices is subject to specific provisions. therefore, this study aimsto review the mechanism for issuing advance payment tax invoices with code 040 throughthe coretax administrative system by identifying the obstacles encountered in the issuanceprocess, as well as the efforts undertaken by pt abc in 2025. furthermore, the researchmethod employed is a qualitative approach obtained through observation during theimplementation of the internship program (pkl), interviews with related parties, anddocumentation studies of tax regulations and relevant company documents. the results ofthe study indicate that pt abc has made efforts to adjust the mechanism for issuing advancepayment tax invoices with code 040 through the coretax administrative system inaccordance with the applicable regulations. however, in practice, several obstacles remain,including slow system performance, errors during the tax invoice upload process,inaccuracies in data entry, differences in the calculation of the tax base (dpp) using the“other value” method, and data inconsistencies resulting from partial delivery of goods.therefore, to address these obstacles, pt abc conducts data re-examinations throughprepared working paper and carries out consultations with the bekasi madya tax serviceoffice (kpp madya bekasi).