Buyer brokerage is the practice of real estate brokers in the United States and Canada representing a buyer in a real estate transaction rather than, by default, representing the seller either directly or as a sub-agent. In the United Kingdom the most common term to describe agent is Buying agent.
In most US states and Canadian provinces, until the 1990s, buyers who worked with an agent of a real estate broker in finding a house were customers of the brokerage, since, by most common law of most states at the time, the broker represented only sellers. Only in the last fifteen years or so have states passed statute law to create buyers' agency.
Today, if the buyer is working with a broker other than the brokerage which "lists" the property, he may choose to enter into a buyer-brokerage agreement to be represented. (In some cases where dual agency is permitted by law, even the listing broker may represent the buyer). If the buyer does not enter into this agreement, he/she remains as a customer of the broker who is then the sub-agent of seller's broker.