Every applicant for a license to act as an agent must have filed with the Commissioner:

The requirement for every applicant for a license to act as an agent to have filed a notice of appointment to do business with the state is essential because it establishes an official record of the agent's intent and ability to operate in that capacity within California. This notice is a necessary step for ensuring that agents are recognized by the state and can conduct business legally.

While the other options might encompass various aspects of regulation and professional standards, they do not directly fulfill the specific requirement needed to initiate licensing. For instance, a proof of income statement might be relevant for proving financial stability, a bond for indemnity relates to providing assurance against possible malpractice or misconduct, and a criminal background check pertains to the individual's fitness for the profession. However, the notice of appointment is specifically tied to formalizing the agent's business relationship with the state and its regulatory authority. This initial filing is crucial as part of the application process for licensing an agent, ensuring compliance with state regulations before one can operate legally.