Final answer:
An agent and their sponsoring broker sign an Independent contractor agreement, which defines the business relationship and terms of commission, duties, and obligations between the two parties.
Step-by-step explanation:
The document signed between an agent and their sponsoring broker is the Independent contractor agreement. This agreement outlines the terms and conditions of the relationship between the real estate agent,
who is the independent contractor, and the broker. It typically includes details regarding commission splits, duties, obligations, and the scope of the agent's independence. Unlike listing contracts and sales contracts, which are agreements between sellers and buyers or agents and their clients for the sale of property, the independent contractor agreement strictly deals with the business relationship between the agent and the broker they work with.