Who must sign a listing agreement for it to be valid?

A listing agreement is a contract between a property owner and a real estate broker that grants the broker the authority to represent the owner in the sale or lease of the property. For this agreement to be valid, it must be signed by the seller, who is the property owner.

When a seller appoints someone else, such as an attorney-in-fact, to manage their real estate transactions, that person is authorized to sign documents on the seller's behalf. However, the signature of an attorney-in-fact is only valid if there is a legally established power of attorney that allows that individual to act for the seller in real estate matters.

Therefore, while an attorney-in-fact's signature can be valid, the primary requirement remains that it is the seller's consent and authority that is crucial for the agreement. The buyer does not typically sign a listing agreement since that agreement directly relates to the duties of the broker in relation to the seller. Similarly, a real estate agent's signature alone does not validate a listing agreement; they must act on behalf of the seller who holds ownership of the property.