What document authorizes the broker to obtain information on the client's behalf?

The document that authorizes a broker to obtain information on the client's behalf is a letter of authority. This document explicitly grants the broker the permission to act on the client’s behalf, allowing them to request and access relevant information necessary for managing the client’s account or financial transactions.

Having a letter of authority in place ensures that there is clear and formal consent from the client, which not only facilitates communication between the broker and third-party institutions but also safeguards the client’s privacy and rights. It provides a legal basis for the broker to operate within the scope defined by the client, making it an essential document in financial and advisory relationships.

The other options do not serve this specific function. A letter of complaint serves to express grievances, an approval agreement typically outlines the terms of an agreement rather than granting authorization for action, and a financial advice statement usually summarizes the recommendations made by a financial advisor instead of authorizing further actions on behalf of the client.