S.C. Code § 12-6-3632
There is allowed as a nonrefundable credit against the tax imposed pursuant to Section 12-6-510 on a full-year resident individual taxpayer an amount equal to one hundred twenty-five percent of the federal earned income tax credit (EITC) allowed the taxpayer pursuant to Internal Revenue Code Section 32.
S.C. Code § 12-6-3632
2017 Act No. 40, Sections 16.B, 16.C, provide as follows:
"B. Notwithstanding Section 12-6-3632, as added by this SECTION, the percentage of the federal earned income tax credit, for which the credit allowed by Section 12-6-3632 is based, must be phased-in in six equal installments of twenty and eighty-three hundredths percent each tax year until it is fully phased-in in tax year 2023, with the twenty and eighty-three hundredths percent applying in tax year 2018.
"C. This SECTION takes effect upon approval by the Governor and applies to tax years beginning after 2017."