Agency relationships with clients versus non-agency relationships with customers
Relationship: Conventionally, the broker provides a conventional full-service, commission-based brokerage relationship under a signed listing agreement with a seller or a "buyer representation" agreement with a buyer, thus creating under common law in most states an agency relationship with fiduciary obligations. The seller or buyer is then a client of the broker. Some states also have statutes that define and control the nature of the representation.
Agency relationships in residential real estate transactions involve the legal representation by a real estate broker (on behalf of a real estate company) of the principal, whether that person(s) is a buyer or a seller. The broker and his licensed real estate salespersons (salesmen or brokers) then become the agents of the principal.
Non-agency relationship: where no written agreement or fiduciary relationship exists, a real estate broker and his sales staff work with a principal who is known as the broker's customer. When a buyer who has not entered into a Buyer Agency agreement with the broker buys a property, that broker functions as the sub-agent of the seller's broker. When a seller chooses to work with a transaction broker, there is no agency relationship created.
Some state Real Estate Commissions - notably Florida's after 1992 (and extended in 2003) and Colorado's after 1994 (with changes in 2003) - created the option of having no agency or fiduciary relationship between brokers and sellers or buyers. Having no more than a facilitator relationship, transaction brokers assist buyers, sellers, or both during the transaction without representing the interests of either party who may then be regarded as customers.
As noted by the South Broward Board of Realtors, Inc. in a letter to State of Florida legislative committees:
"The Transaction Broker crafts a transaction by bringing a willing buyer and a willing seller together and assists with the closing of details. The Transaction Broker is not a fiduciary of any party, but must abide by law as well as professional and ethical standards." (such as NAR Code of Ethics).
The result was that in 2003, Florida created a system where the default brokerage relationship had "all licensees ... operating as transaction brokers, unless a single agent or no brokerage relationship is established, in writing, with the customer" and the statute required written disclosure of the transaction brokerage relationship to the buyer or seller customer only through July 1, 2008.
In the case of both Florida and Colorado, dual agency and sub-agency (where both listing and selling agents represent the seller) no longer exist.
The most recent development in the practice of real estate is "designated agency" which was created to permit individual licensees within the same firm, designated by the principal broker, to act as agents for individual buyers and sellers within the same transaction. In theory therefore, two agents within the same firm act in strict fiduciary roles for their respective clients. Some states have adopted this practice into their state laws and others have decided this function is inherently problematic, just as was dual agency. The practice was invented and promoted by larger firms to make it possible in theory to handle the entire transaction in house without creating a conflict of interest within the firm.
Dual or limited agency
Dual agency occurs when the same brokerage represents both the seller and the buyer under written agreements. Individual state laws vary and interpret dual agency rather differently.
Many states no longer allow dual agency. Instead, "transaction brokerage" provides the buyer and seller with a limited form of representation but without any fiduciary obligations (see Florida law). Buyers and sellers are generally advised to consult a licensed real estate professional for a written definition of an individual state's laws of agency, and many states require written Disclosures to be signed by all parties outlining the duties and obligations.
If state law allows for the same agent to represent both the buyer and the seller in a single transaction, the brokerage/agent is typically considered to be a Dual Agent. Special laws/rules often apply to dual agents, especially in negotiating price.
In some states, Dual Agency can be practiced in situations where the same brokerage (but not agent) represent both the buyer and the seller. If one agent from the brokerage has a home listed and another agent from that brokerage has a buyer-brokerage agreement with a buyer who wishes to buy the listed property, Dual Agency occurs by allowing each agent to be designated as an "intra-company" agent. Only the broker himself is the Dual Agent.
Some laws do allow a broker and one agent to represent both sides of the transaction as dual agents. In those situations, conflict of interest is more likely to occur, typically resulting in the loss of advocacy for both parties.