Cal. Gov. Code § 8213.5

A notary public shall notify the Secretary of State by certified mail or any other means of physical delivery that provides a receipt within 30 days as to any change in the location or address of the principal place of business or residence. A notary public shall not use a commercial mail receiving agency or post office box as his or her principal place of business or residence, unless the notary public also provides the Secretary of State with a physical street address as the principal place of residence. Willful failure to notify the Secretary of State of a change of address shall be punishable as an infraction by a fine of not more than five hundred dollars ($500).