T This Final Project Report is made to determine the reasons for the issuance of the Request for Clarification of Data and/or Information (SP2DK), the process of issuing SP2DK, obstacles encountered in the issuance process of SP2DK, and the effectiveness of SP2DK implementation at the North Jakarta Medium II Tax Office. In conducting this research, the author employed literature review, observation, interviews, and questionnaires as the methods. The research findings indicate that the issuance of SP2DK at the North Jakarta Medium II Tax Office refers to Circular Letter of the Directorate General of Taxes number SE-05/PJ/2022. The conclusion of this Final Project Report is that the reasons for the issuance of SP2DK by the Account Representative are indications of data inconsistency, involvement of third-party data, and indications of errors in tax calculations. Furthermore, the analysis of the effectiveness of SP2DK implementation at the North Jakarta Medium II Tax Office in 2022 and 2023 shows that it is categorized as ineffective and less effective due to the significant number of SP2DK proposed for examination or preliminary examination evidence, as well as existing obstacles therein. Fundamentally, the issuance of SP2DK is not the backbone of tax revenue as SP2DK serves to clarify data and as a form of supervision. It is expected to create a deterrent effect to ensure taxpayers consciously fulfill their tax obligations according to tax regulations, thereby enhancing taxpayer compliance and tax revenue collection.