This research is done at PT Mitra Jasa Agung Medan which engaged in distribution of oil filter. The objective of this study is to of Article 21 Income Tax of permanent employee in increasing tax compliance at PT Mitra Jasa Agung Medan. The method used by the writer in this research is qualitative descriptive method. The writer will conduct tax review of Article-21 Income Tax for the purpose of increasing tax compliance at PT Mitra Jasa Agung Medan. Based on research result, tax review of Article 21 Income Tax can improve tax compliance at PT Mitra Jasa Agung Medan. The company does not calculate the Article 21 –Income Tax in accordance with tax regulation for the permanent employees in year 2017. There are differences between the total Article 21 Income Tax calculated by company and the total Article 21 Income Tax after tax review. The difference is because there are additional income of permanent employees from food allowance, overtime allowance, health allowance and transportation allowance which were not included by the company in Article-21 Income Tax calculation. Besides that, the company stated inaccurate basic salary of the employees. After conducting tax review, the company has to pay the amount of underpaid tax according to the amount of Article-21 Income Tax calculated. The company is recommended to improve the Article-21 Income Tax by calculating it according to the tax regulation. Tax review should also be conducted regularly in the company to increase the company’s tax compliance.