An employing unit shall cease to be an employer subject to this title, only as of the first day of January of any calendar year, if it files with the department, prior to the first day of July of such year, a written application for termination of coverage, and the department finds that the employment in the preceding calendar year was not sufficient to make the employing unit liable under the provisions of §§ 61-1-4 to 61-1-9, inclusive. For the purpose of this section the two or more employing units mentioned in § 61-1-5 or 61-1-6 shall be treated as a single employing unit.
SDCL 61-5-11