Cal. Lab. Code § 203.1
If an employer pays an employee in the regular course of employment or in accordance with Section 201, 201.3, 201.5, 201.6, 201.7, 201.8, or 202 any wages or fringe benefits, or both, by check, draft or voucher, which check, draft or voucher is subsequently refused payment because the employer or maker has no account with the bank, institution, or person on which the instrument is drawn, or has insufficient funds in the account upon which the instrument is drawn at the time of its presentation, so long as the same is presented within 30 days of receipt by the employee of the check, draft or voucher, those wages or fringe benefits, or both, shall continue as a penalty from the due date thereof at the same rate until paid or until an action therefor is commenced. However, those wages and fringe benefits shall not continue for more than 30 days and this penalty shall not apply if the employer can establish to the satisfaction of the Labor Commissioner or an appropriate court of law that the violation of this section was unintentional. This penalty also shall not apply in any case in which an employee recovers the service charge authorized by Section 1719 of the Civil Code in an action brought by the employee thereunder.
Ca. Lab. Code § 203.1