Section 6
SEC. 6. Section thirteen of the same Act is amended to read as follows: "SEC. 13. In consideration of the franchise and rights hereby granted, the grantee shall pay to the National Government during the life of this franchise a tax of two percent of the gross revenue or gross earning derived by the grantee from its operation under this franchise. Such tax shall be due and payable quarterly and shall be in lieu of all taxes of any kind, nature or description, levied, established or collected by any municipal, provincial or National authority: Provided, That if, after the audit of the accounts of the grantee by the Commissioner of Internal Revenue, a deficiency tax is shown to be due, the deficiency tax shall be payable within ten days from the receipt of the assessment. The grantee shall pay the tax on its real property in conformity with existing law."