14 CFR 47.61: Dealer's Aircraft Registration Certificates.

(a) The FAA issues a Dealer's Aircraft Registration Certificate to U.S. manufacturers and dealers to—

(1) Allow manufacturers to make any required flight tests of aircraft.

(2) Facilitate operating, demonstrating, and merchandising aircraft by the manufacturer or dealer without the burden of obtaining a Certificate of Aircraft Registration, AC Form 8050-3, for each aircraft with each transfer of ownership, under subpart B of this part.

(b) A Dealer's Aircraft Registration Certificate is an alternative for the Certificate of Aircraft Registration issued under subpart B of this part. A dealer may, under this subpart, obtain one or more Dealer's Aircraft Registration Certificates in addition to his original certificate, and he may use a Dealer's Aircraft Registration Certificate for any aircraft he owns.

(c) If a Dealer's Aircraft Registration Certificate for an aircraft registered under this subpart expires in accordance with § 47.71, the aircraft owner must submit an application for aircraft registration in accordance with § 47.31 or the assignment of registration number will be canceled in accordance with § 47.15(i)(2).