Section 4
SEC. 4. Section 51 (a) of the National Internal Revenue Code is hereby amended to read as follows: "SEC. 51. Payment and assessment of income tax.—(a) Payment of tax.—(1) In general.—The total amount of tax imposed by this Title shall be paid at the time the return is filed. Such tax shall be paid by the person subject thereto. "If the return is filed after the time prescribed by law (including cases in which an extension of time for filing the return has been granted under section forty-seven of this Code), there shall be paid at the time of such filing the tax or installment which would have been payable on or before such time if the return had been filed within the time prescribed by law, and the remaining installment shall be paid at the time at which, and in the amount in which, it would have been payable if the return had been so filed, subject to the payment of interest at fourteen per centum per annum from the original due date. "In the case of tramp vessels, the shipping agents and/or the husbanding agents, and in their absence, the captains thereof are required to file the return herein provided and pay the tax due thereon before their departure. Failure to file the return and pay the tax, the Bureau of Customs is hereby authorized to hold the vessel and prevent its departure until proof of payment of the tax is presented or a sufficient bond is filed to answer for the tax due. "(2) Installment payments.—When the tax due is in excess of one thousand pesos, the taxpayer other than a corporation taxable under Section 24 and the withholding agents required to deduct and withhold the tax under Sections 53 and 54, all of this Title, may elect to pay the tax in two equal installments, in which case, the first installment shall be paid at the time the return is filed and the second installment, on or before the fifteenth day of July following the close of the calendar year. If any installment is not paid on or before the date fixed for its payment, the whole amount of the tax unpaid becomes due and payable together with the delinquency penalties. "(3) Installment payments for non-resident citizens.—When the tax due from a non-resident citizen is in excess of two hundred dollars (U.S. $200.00), the taxpayer may elect to pay the tax in two equal installments, in which case, the first installment shall be paid at the time the return is filed and the second installment, on or before the fifteenth clay of July following the close of the calendar year. If any installment is not paid on or before the date fixed for its payment the whole amount of the tax unpaid becomes due and payable together with the delinquency penalties."