Cal. Unemp. Ins. Code § 1030
(a) An employer that is entitled under Section 1327 to receive notice of the filing of a new or additional claim may, within 10 days after mailing of the notice, submit to the department any facts within its possession disclosing whether the claimant left the employer’s employ voluntarily and without good cause or left under one of the following circumstances:
(6) The claimant left the employer’s employ to take a substantially better job.
The period during which the employer may submit these facts may be extended by the director for good cause.
(b) A base period employer that is not entitled under Section 1327 to receive notice of the filing of a new or additional claim and is entitled under Section 1329 to receive notice of computation may, within 15 days after mailing of the notice of computation, submit to the department any facts within its possession disclosing whether the claimant left the employer’s employ voluntarily and without good cause or left under one of the following circumstances:
(5) The claimant left the employer’s employ to take a substantially better job.
The period during which the employer may submit these facts may be extended by the director for good cause.