Section 10. Paragraphs (a) (1) and (a) (2), (d) and (e) of Section 51 of the National Internal Revenue Code are 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 twenty 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. Upon failure of the said agents or captains 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 payment. When the tax due is in the excess of two thousand pesos, the taxpayer other than a corporation taxable under Section twenty-four, self-employed individuals who may be required to pay estimated income tax under Chapter X, 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 eighteenth 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."

"(d) Interest on deficiency. Interest upon the amount determined as a deficiency shall be assessed at the same time as the deficiency and shall be paid upon notice and demand from the Commissioner and shall be collected as a part of the tax at the rate of twenty per centum per annum from the date prescribed for the payment of the tax, (or, if the tax is paid in installment from the date prescribed for the payment of the first installment) to the date the deficiency is assessed: Provided, That the maximum amount that may be collected as interest on the deficiency shall in no case exceed the amount corresponding to a period of three years, the present provisions regarding prescription to the contrary notwithstanding."

"(e) Additions to the tax in case of nonpayment. (1) Tax shown on the return. Where the amount determined by the taxpayer as the tax imposed by this Title or any installment thereof, or any part of such amount or installment, is not paid on or before the date prescribed for its payment, there shall be collected as a part of the tax, interest upon such unpaid amount at the rate of twenty per centum per annum from the date prescribed for its payment until it is paid: Provided, That the maximum amount that may be collected as interest on deficiency shall in no case exceed the amount corresponding to a period of three years, the present provisions regarding prescription to the contrary notwithstanding."

"(2) Deficiency. Where a deficiency, or any interest assessed in connection therewith under paragraph (d) of this section, or any addition to the taxes provided for in Section seventy-two of this Code is not paid in full within thirty days from the date of notice and demand from the Commissioner of Internal Revenue, there shall be collected upon the unpaid amount as part of the tax, interest at the rate of twenty per centum per annum from the date of such notice and demand until it is paid: Provided, That the maximum amount that may be collected as interest on deficiency shall in no case exceed the amount corresponding to a period of three years, the present provisions regarding prescription to the contrary notwithstanding."

"(3) Surcharge. If any amount of tax shown on the return is not paid in full on or before the date prescribed for its payment under paragraph (a) of this Section, or any amount of deficiency, and any interest assessed in connection therewith, is not paid in full within the period prescribed in the assessment notice and demand required under paragraph (b) of this Section, there shall be collected in addition to the interest prescribed herein and in paragraph (d) above and as part of the tax a surcharge of ten per centum of the amount of tax unpaid."