Cal. Lab. Code § 3760

Every employer who is insured against any liability imposed by this division shall file with the insurer a complete report of every injury to each employee as specified in Section 6409.1. If not so filed, the insurer may petition the appeals board for an order, or the appeals board may of its own motion issue an order, directing the employer to submit a report of the injury within five days after service of the order. Failure of the employer to comply with the appeals board’s order may be punished by the appeals board as a contempt.