Del. Code tit. 6, § 3102

Whenever a change occurs in the membership of any firm or association which has filed a certificate under § 3101 of this title, a supplemental certificate under the hand of 1 of the members of the firm or association shall, within 10 days after the change, be filed with the Division of Revenue in which it had theretofore filed a certificate, designating the legal name of each and every member comprising the firm or association after the change, and the date when the change took effect, to which certificate shall be attached the affidavit of the person signing it to the effect that the facts therein stated are true and correct.