14 CFR § 48.120 - Invalid registration.
The registration of a small unmanned aircraft is invalid if, at the time it is made -
(a) The aircraft is registered in a foreign country;
(b) The applicant is not the owner, except when the applicant registers on behalf of an owner who is under 13 years of age;
(c) The applicant is not eligible to submit an application under this part; or
(d) The interest of the applicant in the aircraft was created by a transaction that was not entered into in good faith, but rather was made to avoid (with or without the owner's knowledge) compliance with 49 U.S.C. 44101-44103.
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