(A) A taxpayer's taxable year under this chapter must be the same as the taxpayer's taxable year for federal income tax purposes.
(B) If a taxpayer's taxable year is changed for federal income tax purposes, then the taxable year for South Carolina income tax purposes is changed. The taxpayer shall provide the department with a copy of the written permission received from the Internal Revenue Service.
(C) A change in the taxable year of an "S" Corporation is not mandated for South Carolina income tax purposes under Internal Revenue Code Section 1378 unless mandated for federal purposes.
(D) If a change in taxable year results in a taxable year of less than twelve months, South Carolina income tax must be computed in the manner provided in Internal Revenue Code Sections 443(b) (Computation of Tax on Change of Annual Accounting Period) and 443(c) (Adjustment in Deduction for Personal Exemption).