Cal. Bus. & Prof. Code § 4843.5

Except as otherwise provided in this article, an expired certificate of registration may be renewed at any time within five years after its expiration on filing of an application for renewal on a form prescribed by the board, and payment of all accrued and unpaid renewal fees. If the certificate of registration is renewed more than 30 days after its expiration, the registrant, as a condition precedent to renewal, shall also pay the delinquency fee prescribed by this article. Renewal under this section shall be effective on the date on which the application is filed, on the date all renewal fees are paid, or on the date on which the delinquency fee, if any, is paid, whichever occurs last.