California's "dry hire" law for mobile bars means that the service provider cannot sell or provide the alcohol itself; the client must purchase the alcohol for a private event. Mobile bar services in California can provide the bar setup, staff, and mixers, but they legally cannot buy, sell, or transport alcohol unless they have a specific license, which is typically tied to a brick-and-mortar location. A dry hire arrangement requires that the client provides all the alcoholic beverages for the event, which can be a cash bar (if the venue and host have the necessary permits) or a complimentary "hosted bar".