Each subsidiary or affiliate company of a private applicant must file a separate application to become self-insured. They may apply with the parent company or individually, and the same application form is completed by the subsidiary/affiliate.

Group self-insurance by non-affiliated companies is permitted under California regulation, for both private and public sector employers.

Private self-insurers in good standing are permitted to add new subsidiary or affiliate companies with an application for an interim certificate. This provides immediate self-insurance for the new subsidiary/affiliate company and is valid for 180 days. Within the 180-day period, a completed application for a permanent certificate and accompanying documents must be filed and approved prior to the expiration of the interim certificate.