S.C. Code Ann. § 24-21-1190: Compact membership eligibility; effective date; amendments.

(A) Any state is eligible to become a compacting state.

(B) The compact shall become effective and binding upon legislative enactment of the compact into law by no less than thirty-five of the states. The initial effective date must be the later of July 1, 2001, or upon enactment into law by the thirty-fifth jurisdiction. Thereafter, it shall become effective and binding as to any other compacting state, upon enactment of the compact into law by that state. The governors of nonmember states or their designees will be invited to participate in Interstate Commission activities on a nonvoting basis prior to adoption of the compact by all states and territories of the United States.

(C) Amendments to the compact may be proposed by the Interstate Commission for enactment by the compacting states. No amendment shall become effective and binding upon the Interstate Commission and the compacting states unless and until it is enacted into law by unanimous consent of the compacting states.