Employers in South Carolina must conform with these state rules relating to filing income tax withholding returns.
Periodic Returns. Quarterly Form WH-1605 must be filed by the end of the month following the quarter, for the first three quarters. The form for the last quarter is due by the last day of February.
Withheld taxes must be deposited at the same time as federal taxes, using Form WH-1601.
Annual Reconciliation Returns. Form WH-1606 due by the last day of February.