S.D. Codified Laws § 47-1A-402
A person may reserve the exclusive use of a corporate name, including a fictitious name for a foreign corporation whose corporate name is not available, by delivering an application to the Office of the Secretary of State for filing. The application shall set forth the name and address of the applicant and the name proposed to be reserved. If the Office of the Secretary of State finds that the corporate name applied for is available, the Office of the Secretary of State shall reserve the name for the applicant's exclusive use for a nonrenewable one-hundred-twenty-day period.
The owner of a reserved corporate name may transfer the reservation to another person by delivering to the Office of the Secretary of State a signed notice of the transfer that states the name and address of the transferee.
SDCL 47-1A-402