Cal. Bus. & Prof. Code § 7033

Every city or city and county which requires the issuance of a business license as a condition precedent to engaging, within the city or city and county, in a business which is subject to regulation under this chapter, shall require that each licensee and each applicant for issuance or renewal of such license shall file, or have on file, with such city or city and county, a signed statement that such licensee or applicant is licensed under the provisions of this chapter and stating that the license is in full force and effect, or, if such licensee or applicant is exempt from the provisions of this chapter, he shall furnish proof of the facts which entitle him to such exemption.