This research aims to analyze the implementation of tax planning regarding business expenses and its impact on the calculation of Corporate Income Tax (PPh Badan) payable by PT X in Surabaya. Business expenses constitute a crucial component in determining corporate profit; however, not all expenses recognized for accounting purposes are deductible for tax purposes. This discrepancy in treatment between accounting and taxation standards necessitates fiscal adjustments, which in turn affect the amount of income tax payable. The study employs a qualitative descriptive method using a case study approach, with data collection involving the documentation of PT X’s financial statements and tax data. Data analysis was conducted by identifying business expenses, preparing fiscal reconciliations, and comparing Corporate Income Tax calculations before and after the implementation of tax planning for business expenses. The results indicate that implementing tax planning for business expenses at PT X minimizes positive fiscal adjustments and optimizes fiscally deductible expenses. This leads to a reduction in taxable income and, ultimately, lowers the amount of income tax payable legally, without violating applicable tax regulations. Based on the findings, it can be concluded that the proper implementation of tax planning for business expenses—in accordance with tax regulations—enhances the efficiency of the company's tax burden. Therefore, the company is advised to maintain effective management of business expenses and improve its understanding of tax regulations to legally optimize its tax obligations. productivity.