In the United States, real estate brokers and their salespersons (commonly called "real estate agents" or, in some states, "brokers") assist sellers in marketing their property and selling it for the highest possible price under the best terms. When acting as a buyer's agent with a signed agreement (or, in many cases, verbal agreement, although a broker may not be legally entitled to his commission unless the agreement is in writing), they assist buyers by helping them purchase property for the lowest possible price under the best terms. The real estate broker "broker" is obligated to provide fiduciary duties to whomever that broker services as client, this agency relationship can become very confusing; if the broker is helping both the buyer and seller, this is called dual agency. Traditionally, the broker represents the seller, and has a fiduciary duty to the seller. If the broker suggests to the buyer that he will help them negotiate the best price, then it is said the broker is practicing undisclosed dual agency, which is unethical and illegal in all states. Under a dual agency transaction it is vital the broker discloses to either/or part whom they represent as client, and whom they represent as customer. A real estate broker owes his client fiduciary duties, those duties include care, confidentiality, loyalty, obedience,accounting & disclosure. A real estate broker owes his customer fair & honest dealing. A real estate broker must request all parties(seller & buyer)sign a dual agency agreement, to protect their license.