S.D. Codified Laws § 10-45-20.5
There are specifically exempted from the provisions of this chapter and the computation of the tax imposed by it, gross receipts from the sale of services rendered by a related corporation as defined in subdivision 10-43-1(11) for use by a financial institution as defined in subdivision 10-43-1(4) or on any service rendered by a financial institution as defined in subdivision 10-43-1(4) for use by a related corporation as defined in subdivision 10-43-1(11). For the purposes of this section, the term, related corporation, includes a corporation which together with the financial institution is part of a controlled group of corporations as defined in 26 U.S.C. § 1563 as in effect on January 1, 1989, except that the eighty percent ownership requirements set forth in 26 U.S.C. § 1563(a)(2)(A) for a brother-sister controlled group are reduced to fifty-one percent. The exemption provided in this section does not apply to the lease of tangible personal property or any product transferred electronically unless the sales or use tax has been paid on the property by the lessor.
SDCL 10-45-20.5