Tax deductions and credits must generally be taken in the taxable year they are paid or accrued/incurred, with special timing rules for certain federal tax deductions and a bar on claiming the same deduction twice.
§93. Period for which deductions and credits shall be taken A. Except as hereinafter provided in this Section, the deductions and credits provided for in this Chapter shall be taken for the taxable year in which "paid or accrued" or "paid or incurred," dependent upon the method of accounting upon the basis of which the net income is computed, unless in order to clearly reflect the income the deductions or credits should be taken as of a different period. B. The proper year in which to claim deductions for federal income and excess profits taxes allowable under the provisions of R.S. 47:55 shall be determined as follows, regardless of the method of accounting regularly employed by the taxpayer: (1) The amount of tax shown to be due upon the federal income tax return of the taxpayer, as filed, shall be allowed as a deduction in the state return for the same period as that for which such federal return is filed. (2) Federal income and excess profits taxes paid after the filing of the federal return in addition to the amount disclosed to be due by the return as filed shall be allowed as a deduction in the state return for that period if it is not prescribed. If it is prescribed, the deduction for such additional taxes shall be allowed as a deduction in the state return for the period in which such additional tax is paid. This Subsection shall apply to all such payments after December 31, 1973. C. If a deduction is claimed and allowed in any period, the same deduction cannot again be claimed in a subsequent period in which it otherwise would be properly deductible, unless the taxpayer, prior to the running of prescription with respect to the first period, shall have amended his return for that period so as to eliminate the deduction and shall have paid any additional tax which may be due as a result thereof, together with any interest and penalties that may be applicable thereto. Amended by Acts 1970, No. 258, §4; Acts 1973, Ex.Sess., No. 8, §1; Acts 2016, 1st Ex. Sess., No. 30, §1.