Title II — TAX ON INCOME shall be allowed as a deduction (in addition to the contributions to such trust during the taxable year to cover the pension liability accruing during the year, allowed as a deduction under Subsection (A)(1) of this Section) a reasonable amount transferred or paid into such trust during the taxable year in excess of such contributions, but only if such amount: (1) has not theretofore been allowed as a deduction, and (2) is apportioned in equal parts over a period of ten (10) consecutive years beginning with the year in which the transfer or payment is made. (K) Additional Requirements for Deductibility of Certain Payments. — Any amount paid or payable which is otherwise deductible from, or taken into account in computing gross income or for which depreciation or amortization may be allowed under this Section, shall be allowed as a deduction only if it is shown that the tax required to be deducted and withheld therefrom has been paid to the Bureau of Internal Revenue in accordance with this Section, Sections 58 and 81 of this Code. (L) Optional Standard Deduction. — In lieu of the deductions allowed under the preceding Subsections, an individual subject to tax under Section 24, other than a nonresident alien, may elect a standard deduction in an amount not exceeding forty percent (40%) of his gross sales or gross receipts, as the case may be. In the case of a corporation subject to tax under Sections 27(A) and 28(A)(1), it may elect a standard deduction in an amount not exceeding forty percent (40%) of its gross income as defined in Section 32 of this Code. Unless the taxpayer signifies in his return his intention to elect the optional standard deduction, he shall be considered as having availed himself of the deductions allowed in the preceding Subsections. Such election when made in the return shall be irrevocable for the taxable year for which the return is made: Provided, That an individual who is entitled to and claimed for the optional standard deduction shall not be required to submit with his tax return such financial statements otherwise required under this Code: Provided, further, That a general professional partnership and the partners comprising such partnership may avail of the optional standard deduction only once, either by the general professional partnership or the partners comprising the partnership:24 Provided, finally, That except when the Commissioner otherwise permits, the said individual shall keep such records pertaining to his gross sales or gross receipts, or the said corporation shall keep such records pertaining to his gross income as defined in Section 32 of this Code during the taxable year, as may be 24 60 Introduced by Section 11 of the TRAIN Law. Isla Lipana & Co., the Philippine member firm of the PwC network