Tax is the contribution from society to the state or country authorities. It is an obligation for all individuals to pay tax, including companies. Many companies try to lower tax in order to have more tax saving. Different companies have various ways to minimize the tax. One of the method being used will be tax planning. The objective of this research is to understand the usage of tax planning on PT. Sumatra Industri Cat by comparing gross and gross up method. The result of research indicates that PT. Sumatra Industri Cat can minimize the income tax by applying gross up method in calculating Article 21- Income tax as tax allowances given to the employees can be expensed. Therefore, PT. Sumatra Industri Cat will gain more tax saving.