Cal. Bus. & Prof. Code § 5616
(a) A landscape architect shall use a written contract when contracting to provide professional services to a client pursuant to this chapter. The written contract shall be executed by the landscape architect and the client, or their representatives, prior to the landscape architect commencing work, unless the client knowingly states in writing that work may be commenced before the contract is executed. The written contract shall include, but not be limited to, all of the following:
(4) A statement in at least 12-point type that reads:
“Landscape architects are licensed by the Landscape Architects Technical Committee located at 2420 Del Paso Road, Suite 105, Sacramento, CA 95834.”
(b) This section does not apply to any of the following:
(4) Professional services rendered by a landscape architect to any of the following: