14 C.F.R. § 48.115
(b) The holder of a Certificate of Aircraft Registration must update the information using the web-based small unmanned aircraft registration system within 14 calendar days of the following:
[Doc. No. FAA-2015-7396; Amdt. No. 48-1; 80 FR 78645, Dec. 16, 2015. Redesignated and amended by Doc. No. FAA-2019-1100; Amdt. No. 48-3, 86 FR 4504, Jan. 15, 2021]