Cal. Bus. & Prof. Code § 23661

(a) Except as otherwise provided in this section, alcoholic beverages shall be brought into this state from without this state for delivery or use within the state only by common carriers and only when the alcoholic beverages are consigned to a licensed importer, and only when consigned to the premises of the licensed importer or to a licensed importer or customs broker at the premises of a public warehouse licensed under this division.
(b) The provisions of this chapter are not applicable in the case of alcoholic beverages which are sold and delivered by a licensee in this state to another licensee in this state, and which in the course of delivery are taken without this state through another state without any storage thereof in such other state.
(c) The provisions of subdivision (a) are not applicable in the case of a reasonable amount of alcoholic beverages brought into this state by an adult from without the United States for personal or household use, except that a California resident returning to the United States by a vehicle that is not a common carrier, or any adult entering the United States as a pedestrian, shall be restricted to the amount of alcoholic beverages which are exempt from the payment of duty in accordance with existing provisions of federal law. These alcoholic beverages shall be exempt from state licensing restrictions.
(d) The provisions of subdivision (a) are not applicable to incidental amounts of alcoholic beverages brought into this state by an adult for personal use from a hotel that is jointly located within the jurisdictions of this state and Nevada.
(e) The provisions of subdivision (a) are not applicable in the case of alcoholic beverages shipped into this state from without the United States by an adult member of the Armed Forces of the United States, serving outside the confines of the United States, for their personal or household use within the state in such quantity of alcoholic beverages as is exempt from the payment of duty under existing provisions of the Federal Tariff Act or regulations. These alcoholic beverages may be brought into this state only by common carrier and consigned to the premises of a licensed importer or customs broker, or to a licensed importer or customs broker at the premises of a public warehouse licensed under this division. Notwithstanding any other provisions of this division, the holder of an importer’s license, a customs broker’s license, or a public warehouse license, may make delivery of such alcoholic beverages as may be brought into this state under the provisions of this paragraph directly to the owner thereof upon satisfactory proof of identity. This delivery shall not be deemed to constitute a sale in this state.
(f) A manufacturer of distilled spirits shall transport such distilled spirits into this state in motor vehicles owned by or leased to the manufacturer, and operated by employees of the manufacturer, only if all of the following apply:
1. (1) The distilled spirits are transported into this state from a place of manufacture within the United States.
2. (2) The manufacturer holds a California distilled spirits manufacturer’s license.
3. (3) Delivery is made to the licensed premises of such distilled spirits manufacturer.