California Code, Business and Professions Code - BPC § 3070

(a) Before engaging in the practice of optometry, each licensed optometrist shall notify the board in writing of the address or addresses where he or she is to engage in the practice of optometry and, also, of any changes in his or her place of practice. After providing the address or addresses and place of practice information to the board, a licensed optometrist shall obtain a statement of licensure from the board to be placed in all practice locations other than an optometrist's principal place of practice.The practice of optometry is the performing or the controlling of any of the acts set forth in Section 3041.

(b) A licensed optometrist is not required to provide the notification described in subdivision (a) if he or she engages in the temporary practice of optometry. “Temporary practice” is defined as the practice of optometry at locations other than the optometrist's principal place of practice for not more than five calendar days during a 30-day period, and not more than 36 days within a calendar year. This limitation shall apply to all practice locations where the licensed optometrist is engaging in temporary practice, not to each practice location individually. If the time period of the temporary practice needs to be extended for any reason, the licensed optometrist shall submit an application for a statement of licensure to the board pursuant to Section 1506 of Title 16 of the California Code of Regulations.

(c) Notwithstanding Section 3075, an optometrist engaging in the temporary practice of optometry at a location described in subdivision (b) shall carry and present upon demand evidence of his or her licensure but shall not be required to post his or her current license or other evidence of current license status issued by the board.

(d) In addition to the information required by Section 3076, a receipt issued to a patient by an optometrist engaging in the temporary practice of optometry at a location described in subdivision (b) shall contain the address of the optometrist's primary practice location and the temporary practice location where the services were provided.