S.D. Codified Laws § 5-18A-51
A request for proposal, an invitation to bid, or any other document issued by a purchasing agency, with the intent of soliciting responses for the potential award of a contract, must include notice of the certification requirement of this section.
Each bidder or offeror shall, at the time a bid or offer is submitted, or at the time a contract that is subject to § 5-18A-14, 5-18A-40, 5-18B-29, 5-18B-44, or 5-18D-17 is awarded or renewed, certify, in writing, that the bidder or offeror is not a prohibited entity.
If at any time thereafter, any party to a contract subject to § 5-18A-14, 5-18A-40, 5-18B-29, 5-18B-44, or 5-18D-17 becomes a prohibited entity, that party must provide written notification to the purchasing agency. Upon receiving the notification, the agency may terminate the contract.
SDCL 5-18A-51