Cal. Rev. & Tax. Code § 6043.1

A marketplace facilitator that is registered with the department or required to register with the department under any law that imposes a fee administered pursuant to Part 30 (commencing with Section 55001) and that facilitates a retail sale of tangible personal property by a marketplace seller is the retailer or dealer or both for purposes of collecting and remitting any fee imposed on the consumer in regards to that retail sale.