Cal. Business and Professions Code § 7839.2

(a) A professional geologist or professional geophysicist shall use a written contract when contracting to provide geological or geophysical services to a client pursuant to this chapter. The written contract shall be executed by the professional geologist or professional geophysicist and the client or the client’s representative prior to the professional geologist or professional geophysicist commencing work, unless the client states in writing that work may be commenced before the contract is executed. The written contract shall include, but is not limited to, all of the following: (1) A description of the services to be provided to the client by the professional geologist or professional geophysicist. (2) A description of any basis of compensation applicable to the contract, and the method of payment agreed upon by the parties. (3) The name, address, and license or certificate number of the professional geologist or professional geophysicist, and the name and address of the client. (4) A description of the procedure that the professional geologist or professional geophysicist and the client will use to accommodate additional services. (5) A description of the procedure to be used by both parties to terminate the contract. (6) Disclosure of any existence of a current professional liability insurance policy covering the professional geologist or professional geophysicist in responsible charge of the services. (b) Subdivision (a) shall not apply to any of the following: (1) Geologic or geophysical services rendered by a professional geologist or professional geophysicist for which the client will not pay compensation. (2) A geologist or geophysicist who has a current or prior contractual relationship with the client to provide geologic or geophysical services, and who has already been paid the fees that are due under the contract by the client. (3) If the client executes a waiver in writing after full disclosure of this section that a contract that complies with the requirements of this section is not required. (4) Geological or geophysical services rendered by a geologist or geophysicist to any of the following: (A) A geologist or geophysicist licensed under this chapter. (B) An engineer licensed under Chapter 7 (commencing with Section 6700). (C) A land surveyor licensed under Chapter 15 (commencing with Section 8700). (D) An architect licensed under Chapter 3 (commencing with Section 5500). (E) A contractor licensed under Chapter 9 (commencing with Section 7000). (F) A public agency. (c) As used in this section, “written contract” includes a contract in electronic form.