1 September 2020 Update
The Board of Equalization still exists but no longer handles sales tax. The California Department of Tax and Fee Administration (CDTFA) now handles sales tax. Publication 52, which is still available, is now on the CDTFA website. See link below.
The California State Board of Equalization ("Board") released guidance on vehicle and vessel transfers that are not subject to California use tax.
California taxes sales of vehicles and vessels ("vehicles") unless an exemption applies. When a vehicle is purchased from a dealer in California, the dealer is responsible for reporting and paying sales tax. When a vehicle is purchased from someone other than a dealer, the purchaser must pay use tax. The use tax rate is generally the rate that applies where the vehicle is registered or moored. The sales tax rate is generally the rate that applies where the vehicle is sold. Purchasers can pay use tax either to the Department of Motor Vehicles ("DMV") when they register the vehicle or directly to the Board.
California exempts some vehicle sales to individuals by non-dealers. A vehicle is exempt from use tax when it is (1) received as a gift, (2) purchased from a family member, (3) involuntarily obtained through inheritance or court order, (4) received in the dissolution of a company, (5) purchased and delivered out of state without being used, (6) purchased and delivered out of state by active duty military personnel who then transfer to California and bring the vehicle with them, (7) purchased by the U.S. government, (8) purchased for out-of-state use and only used in California while being removed from the state, or (9) purchased by an American Indian for use on a reservation.
If a purchaser qualifies for a use tax exemption, the purchaser may get a Use Tax Clearance certificate from the Board. This certificate allows the purchaser to register the vehicle in California without paying use tax. The DMV can process vehicle registrations without this certificate but is not required to do so.