From Consumer Wiki
A time-sharing program involves long-term rights to use and occupy real property for short-term use periods into which the property has been divided (for example, the right to use a dwelling unit for two weeks of each year for the next 10 years).
A public report must be obtained from the Department of Real Estate before sales of 12 or more time-share interests in real property located within California can be made in this state. If the time-share interests to be offered in California are in real property located outside of the state, the Department of Real Estate derives its regulatory authority from the Business and Professions Code Section 10250, et seq., and a permit rather than a public report is a prerequisite to an offering for sale.
California Department of Real Estate
1651 Exposition Blvd.
Sacramento, CA 95815
Phone Number: CalBRE Public Information Line – 1-877-373-4542
Los Angeles: (213) 620-2072 Main line
Los Angeles: (213) 576-6903 Enforcement
(213) 576-6942 Fax
San Diego: (619) 525-4192
A corporation selling timeshares is also regulated by the Department of Business Oversight:
California Department of Business Oversight
980 - 9th Street, #500
Sacramento, CA 95814