N.C. Gen. Stat. § 90-118.2
The license and the current certificate of renewal of license to practice optometry issued, as herein provided, shall at all times be displayed in a conspicuous place in the office of the holder thereof and whenever requested the license and the current certificate of renewal shall be exhibited to or produced before the North Carolina State Board of Examiners in Optometry or to its authorized agents.
A licensee who practices in more than one office location shall make application to the Board for a duplicate license for each branch office for display as required by this section. In issuing a duplicate license, the address of the branch office location and the original certificate number shall be included. At the time of the annual renewal of licenses, those optometrists who have been issued a duplicate license for a branch office, shall make application to the North Carolina Board of Examiners in Optometry on a form provided by the Board for the renewal of the license in the same manner as provided for in G.S. 90-118.10 for the renewal of his license. The holder of a certificate for a branch office may cancel it by returning the certificate to the Secretary of the Board.
N.C. Gen. Stat. § 90-118.2