Which document must be signed by the seller to grant authority to a real estate agent to sell property?

The listing agreement is the key document that must be signed by the seller to grant authority to a real estate agent to sell property. This agreement establishes a formal relationship between the seller and the real estate agent, outlining the terms of the agent’s representation, including the duration of the agreement, the commission rate, and the responsibilities of both the seller and the agent.

In this context, a listing agreement signifies the seller's consent for the agent to act on their behalf in promoting and negotiating the sale of the property. It is a crucial step in the real estate process, providing legal authority for the agent to market the property and represent the seller's interests.

The other options serve different purposes: a purchase agreement is a contract between a buyer and a seller detailing the sale, not a means to authorize an agent; a sales contract is typically used after a buyer is found and involves the terms of the transfer; and a seller's disclosure provides potential buyers with information about the property's condition but does not grant any authority to an agent.