Del. Code Ann. tit. 19, § 3342
Except as otherwise provided in § 3343 of this title, an employing unit shall cease to be an employer subject to this chapter only as of January 1 of any calendar year if it files with the Department, prior to January 5 of such year, a written application for termination of coverage and the Department finds that there was no employment as defined in § 3302(12)(A) and (14)(C) of this title performed for an employing unit within the preceding calendar year.
For purposes of this section, the 2 or more employing units mentioned in § 3302(12)(D), (12)(E) or (12)(F) of this title shall be treated as a single employing unit.
41 Del. Laws, c. 258, § 8; 19 Del. C. 1953, § 3342; 57 Del. Laws, c. 669, § 5B; 58 Del. Laws, c. 143, § 8; 58 Del. Laws, c. 522, § 22; 84 Del. Laws, c. 365, § 11