S.C. Code § 40-55-110
At its discretion the board may at any time waive the assembled examination and grant the appropriate license upon payment of the required fee to any person who meets the requirement of Section 40-55-80 and who is qualified by educational and professional attainments to the satisfaction of the board if it deems such action to be in the public interest. The board may also in its discretion grant a license without an assembled examination to any person residing or employed in the State who at the time of application is licensed or certified by a similar board of another state whose standards, in the opinion of the board, are not lower than those required by this chapter, or who has been practicing psychology in another state and has qualifications not lower than those required by this chapter, and is able to satisfy the board that to grant him a license would be in the public interest, or who has been certified by the American Board of Examiners in Professional Psychology. A person or firm of consultants not licensed in this State and nonresidents of this State who wishes to perform practices under the provisions of this chapter for a period not to exceed sixty days within a calendar year, must petition the board for a temporary permit to perform such practices. If the petitioner is licensed or certified in another state deemed by the board to have standards equivalent to those set forth in this chapter, a permit will be issued for a fee to be fixed by the board.
S.C. Code § 40-55-110