Do I need to give a forwarding address to my California landlord at move-out?

Yes. Most California statutes (and Cal. Civ. Code 1950.5(h)(1)) condition the deposit return on the tenant providing a forwarding address. Without it, the landlord can hold the deposit until contacted. Provide the forwarding address in writing (email or letter) on or before move-out, with a clear request for return of the deposit. Up to twice the wrongfully withheld amount if the court finds bad faith. Attorney fees also recoverable. The forwarding address is the address where the landlord must send the deposit and itemized statement; if the tenant changes it, the tenant should update the landlord.

Source: Cal. Civ. Code 1950.5(h)(1)