Cal. Bus. & Prof. Code § 7881
Except as otherwise provided in this article, certificates of registration as a geologist or as a geophysicist, or certified specialty certificates, may be renewed at any time within five years after expiration on filing an application for renewal on a form prescribed by the board and payment of all accrued and unpaid renewal fees. If the certificate is renewed more than 30 days after its expiration, the certificate 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 all renewal fees are paid, or on the date on which the delinquency fee, if any, is paid, whichever last occurs. If so renewed, the certificate shall continue in effect through the date provided in Section 7880 that next occurs after the effective date of the renewal, when it shall expire if it is not again renewed.
Ca. Bus. and Prof'l. Code § 7881