South Dakota Planning Company (SDPC) is an ultra-high net worth trust planning firm, founded by Al W. King III and Pierce H. McDowell III, that advises both domestic and international clients. SDPC, a Delaware LLC doing business in New York City and Westport, Connecticut, works closely with its sister company, South Dakota Trust Company LLC (SDTC), which is an independent trust company, headquartered in Sioux Falls, South Dakota, specializing in providing trust administration for the wealthy. South Dakota Planning Company is responsible for sales, marketing and technical support, as well as publications, speeches, trust planning and consulting to support South Dakota Trust Company LLC.

Adding to the SDPC office in New York City, South Dakota Planning Company also opened an office in Westport, CT in 2018. Located in Connecticut’s Fairfield County, SDTC Planning of CT works closely with its affiliated companies, and advises both international and domestic clients on their trust and estate planning. Absolutely no trust administration is done out of the New York City and Westport offices.