S.D. Codified Laws § 55-18-6
Current with legislation signed by the governor on or before 3/6/2024
When notice is made on, or consent obtained from, co-representatives, notice on, or consent from, all acting co-representatives is required except when the terms of the co-representatives' authority provide that the co-representatives may act independently or by other means.
However, when a representative is acting pursuant to subdivision 55-18-9(3), (4), or (7), consent from or notice to one representative is sufficient to bind the person represented.
SDCL 55-18-6