S.C. Code § 38-9-100
If a qualified insurer deposits with an officer or official body of another state for the protection of all its policyholders, or all its policyholders and creditors, acceptable securities not in default as to principal or interest and of a current market value of not less than one million dollars, and delivers to the director or his designee a certificate to that effect, authenticated by the appropriate state official holding the deposit, the insurer may be relieved of making the deposit required by Section 38-9-80. For the purpose of this section a 'qualified insurer' is a licensed stock insurer possessed of at least ten million dollars of capital and surplus or a licensed mutual, fraternal, or reciprocal insurer possessed of at least ten million dollars of surplus, according to its most recent annual statement filed with the director or his designee and, in the discretion of the director or his designee, may include eligible surplus lines insurers which meet these capital and surplus requirements. For the purpose of this section, "acceptable securities" means bonds of the United States or of a state of the United States, or of a municipality or county, upon which is pledged the full faith and credit of the appropriate political division, or bonds or notes secured by mortgages or deeds of trust on otherwise unencumbered real estate of a market value of not less than double the amount loaned, or other securities approved by the director or his designee.
S.C. Code § 38-9-100