Cal. BPC § 5070.6

Except as otherwise provided in this chapter, an expired permit may be renewed at any time within five years after its expiration upon the filing of an application for renewal on a form prescribed by the board, payment of all accrued and unpaid renewal fees and providing evidence satisfactory to the board of compliance as required by Section 5070.5. At the time of application, if the applicant has a valid email address, the applicant shall provide that address to the board. If the permit is renewed after its expiration, its holder, as a condition precedent to renewal, shall also pay the delinquency fee prescribed by this chapter. Renewal under this section shall be effective on the date on which the application is filed, on the date on which the accrued renewal fees are paid, or on the date on which the delinquency fee, if any, is paid, whichever last occurs. If so renewed, the permit shall continue in effect through the date provided in Section 5070.5 that next occurs after the effective date of the renewal, when it shall expire if it is not again renewed.