The below is from South Dakota Department of Revenue. Seems like they did their homework.

Receipts for title search and examination and other services thatare in addition to the premium charge are subject to sales tax, except for filing or recording fees and taxes that the client is legally liable for.

 Fees from a title search or examination are subject to sales tax. If the title search fee is included in the gross all-inclusive premium, and there are no additional charges, the premium is not subject to sales tax.

 Countersignature Fees. A title or abstract company can only search records in the county they are located in or in counties they have the appropriate “title plant” for (record of register of deeds records). If they are contacted to do a title search of land in another county, they will contact the title or abstract company in the county where land is located. That title or abstract company does the search and countersigns — they sign off on the search of the records in that county. This is a sale for resale. The company purchasing the service should issue an exemption certificate to the title or abstract company that performed the search. The company providing the service to the client is responsible for remitting sales tax, if applicable, on their receipts. Example: Title Company A in Pierre is contracted to search property in Stanley County. Title Company A contracts Title Company S in Ft. Pierre to complete the title search. Title Company S bills Title Company A for the search. Title Company A should furnish Title Company S an exemption certificate. Title Company S does not owe sales tax on this transaction if they have received the exemption certificate. Title Company A is responsible for sales tax on their receipts for this service