Abstract: Income tax is an important component of the company, where the tax information in the financial statements has its administration. This tax planning is used by almost every company in carrying out tax management to get the highest possible income and reduce the lowest possible costs. This study aims to formulate the form of corporate policy in planning PPh Article 21, whether it is following the applicable taxation tax provisions, and to see the effectiveness and optimization of PPh Article 21 planning at PT CAS to minimize corporate tax payments. The calculating PPh Article 21 uses the Net method, a method of withholding tax where the company bears Income Tax Article 21 for employees. The Gross-Up method is a method of withholding taxes.