This research is done at PT Komitama Maju Perkasa. The company is engaged in manufacturing PET (Polyethylene Terephthalate) flakes. The objective of this study is to know the implication of gross up method of Article 21 Income Tax on entity income tax at PT Komitama Maju Perkasa. The methods used by the writer in this research are qualitative descriptive method. This research will implement tax planning of Article 21 Income Tax with gross up method and comparing with the net method in order to know the impact of gross up method on income tax payment. Based on research result, conclusion of this research is that the implementation of gross up method on Article 21 Income Tax can give impact in decreasing of entity income tax at PT Komitama Maju Perkasa. The implementation of gross up method can cause the difference in recognition of deductible expense in determining taxable income with net method. The amount of deductible expense in calculation of entity income tax with implementation of gross up method is higher than before implementation of gross up method. By this, it can decrease entity income tax. However, implementation of gross up method of Article 21 Income Tax can increase Article 21 Income Tax because company must include tax allowance as taxable object of Article 21 Income Tax. Gross up method can give tax payment efficiency for both employee and company. With gross up method, company can make tax saving of entity income tax in amount of Rp 28,132,750.00 in year 2017. It can conclude that gross up method is a good alternative in making tax saving.