S.C. Code Ann. § 40-3-270

(A) A firm desiring a certificate of authorization shall file with the board an application on forms provided by the board and pay an application fee. Before a certificate of authorization may be issued to an out-of-state business or professional corporation, the corporation must be approved to transact business in this State. A copy of the approved certificate of authority issued by the State must be filed with the board application. (B) A firm must maintain on file in the board office the name of the individual in full authority and responsible charge and written evidence of authority. Failure to provide accurate and timely information may constitute a violation of this subsection. (C) For the purpose of this chapter, a sole proprietorship means a business in which one or more registered architects are engaged as employees; however, the practice must be conducted under the name registered with the board as an individual (i.e., John Doe, Architect). Any other practice name, i.e., Doe & Company, or Doe & Associates, requires a certificate of authorization to practice. (D) If a South Carolina firm seeks to register under a name referring to persons rather than a trade name, the persons referred to in the firm's name must be licensed as individual architects, engineers, land surveyors, or landscape architects in this State. (E) If an out-of-state firm seeks to register under a name referring to persons rather than a trade name, the persons referred to in the firm's name must be licensed as individual architects, engineers, land surveyors, or landscape architects in this State or in another state or jurisdiction. (F) The requirement to obtain a certificate of authorization applies to associations for one or more projects but does not apply to an out-of-state firm or individual retained by a registered South Carolina architect as a consultant only. (G) A registered architect practicing in his name who does not employ a registered architect is not required to obtain a certificate of authority.