Del. Code tit. 3, § 1210

All licenses shall continue in effect until December 31 of the year in which the license expires, whereupon they shall become invalid unless renewed, except that a license for which a renewal application has been submitted to the Department by November 30 shall remain in full force and effect until such time as the Department gives written notice to the license holder of renewal or denial. Forms for renewal shall be mailed to all holders of current licenses by the Department by October 1 of the year in which they expire.