S.D. Codified Laws § 10-59-27
Any taxpayer who has received written advice from the Department of Revenue concerning the taxability of transactions shall be allowed to rely on such advice when filing tax returns. However, the taxpayer shall maintain a copy of the advice in the taxpayer's business records. The department may not maintain a position against a taxpayer which is inconsistent with a prior written opinion issued to the same taxpayer unless rescinded by the department, by a change in statutory law or reported case law, by a change in federal interpretation in cases if the department's written advice was predicated upon a federal interpretation or by a change in material facts or circumstances relating to the taxpayer. For the purposes of this section, written advice includes municipal boundary information, and zip codes and addresses located within municipalities provided by the department.
SDCL 10-59-27