S.C. Code Ann. § 12-6-3910 — Estimated tax payments form; due dates; treatment of excess where estimated payments or withholdings more than tax liability; waiver of penalties

(A) South Carolina estimated tax payments must be made in a form prescribed by the department in accordance with Internal Revenue Code Sections 6654 and 6655 except that:
(1) the small amount provisions in Internal Revenue Code Sections 6654(e)(1) and 6655(f) are one hundred dollars;
(2) income for the first installment for corporations is annualized using the first three months of the taxable year;
(3)(a) The due dates of the installment payments for calendar year taxpayers other than corporations are:
First quarter:
April 15
Second quarter:
June 15
Third quarter:
September 15
Fourth quarter:
January 15 of the following taxable year.
(b) The due dates of the installment payments for calendar year corporations are:
First quarter:
April 15
Second quarter:
June 15
Third quarter:
September 15
Fourth quarter:
December 15.
(c) In applying the estimated tax payment provisions to a taxable year beginning on a date other than January 1, the month that corresponds to the months specified above must be substituted.
(B) Payments required by this section are considered payments on account of income taxes imposed by this chapter and license fees imposed by Chapter 20 for the taxable year designated.
(C) To the extent that estimated tax payments and withholdings are in excess of the taxpayer's income tax and license fee liability as shown on the income tax return, the taxpayer may claim a:
(1) refund; or
(2) credit for estimated tax for the succeeding taxable year.
(D) For corporate taxpayers, estimated tax payments will be deemed to apply first to income taxes and then apply to license fees.
(E) The department may waive estimated tax payment penalties for corporations that calculate South Carolina estimated tax payments based on a federal law that increases estimated tax payments in one estimated tax payment period and decreases estimated tax payments for one estimated tax payment period, or changes the dates estimated tax payments are due for not more than one month.