S.C. Code Ann. § 38-73-520

Every insurer must file with the department, except as to exempt commercial policies, every manual of classifications, rules, and rates, every rating plan, and every modification of any of these which it proposes to use. The filing exemption shall not apply to loss cost filings by advisory or rating organizations or to the multiplier for expenses, assessments, profit, and contingencies and any modifications to loss costs used by a workers' compensation insurer to be applied to approved loss costs to develop the insurer's rates as provided in Section 38-73-525. Every filing must state the proposed effective date and indicate the character and extent of the coverage contemplated.