California Code, Penal Code - PEN § 28016

(a) If the PPO ceases to do business, ceases to possess a valid PPO license issued by the bureau that is not suspended, revoked, expired, inactive, delinquent, or canceled, ceases as a business entity, or changes its type of business formation, the PPO shall, within 30 days and unless otherwise prohibited by law, lawfully sell or transfer all PPO-owned firearms.

(b) A PPO shall notify the department of the sale or transfer of a PPO-owned firearm within five business days of the transaction in a manner prescribed by the department. This subdivision shall not apply if the sale or transfer was made to or through a licensed firearms dealer pursuant to Chapter 5 (commencing with Section 28050).