S.D. Codified Laws § 10-45A-10 (2026)
Claims for refund shall include such documentary evidence as the secretary of revenue deems necessary to assure validity of the claim.
Source: SL 1974, ch 89 , § 7; SL 2003, ch 272 (Ex. Ord. 03-1), § 82; SL 2011, ch 1 (Ex. Ord. 11-1 ), § 161, eff. Apr. 12, 2011.