CHICAGO, July 20 — The National Association of Realtors stands as one of those curious American institutions: a private trade body with quasi-regulatory heft over the nation’s property market, underwritten by a federal trademark and a code of ethics it wrote for itself in 1913.
As of December 2023, NAR counted more than 1.5 million members, making it the largest trade association in the United States — a sprawling membership of brokers, salespeople, property managers, appraisers and counsellors, each state-licensed and each bound to a set of standards the association first adopted before the First World War. The organisation began life on May 12, 1908, as the National Association of Real Estate Exchanges in Chicago, where its headquarters remain.
It became the National Association of Real Estate Boards in 1916 and settled on its current name in 1972. Along the way it secured a U.S. trademark on the word “Realtor” and built what amounts to a self-regulatory apparatus for real estate brokerage. Under the hood, the real power lies in its governance of several hundred local Multiple Listing Services — the databases that brokers rely on to share property data.
NAR sets the policies for most of those MLSs.
Digital evolution and antitrust friction
In the late 1990s, as the Internet began to reshape commerce, NAR adapted its rules to permit Internet Data Exchanges — systems under which brokers allow a portion of their listing data to appear on agents’ or brokers’ websites. It also created rules for Virtual Office Websites, which require potential buyers to register before viewing listings. The technical reality, however, is that these innovations arrived with strings attached.
Listing brokerage information must be placed on every public display to prevent misrepresentation — a detail that matters because it maintains the traditional intermediary’s role even in a digital environment. The tension between the old guard and the new breed of internet-based brokers came to a head in 2005, when the U.S. Department of Justice filed an antitrust lawsuit against NAR.
The DOJ alleged that the association’s MLS rules on data display were a product of a conspiracy to restrain trade, specifically by excluding internet-based brokers from the market. NAR’s response: it proposed an Internet Listing Display system that ultimately became the IDX framework still in use today. As ever, the trade body’s moves have been a balancing act between preserving member control and accommodating the technological shifts that buyers and sellers now expect.
What to watch next
NAR has continued to push digital transformation initiatives, including work on technology standards and data-sharing frameworks. With an MLS system that it largely governs, and a membership that spans the entire licensed real estate industry, the association remains the central gatekeeper of residential and commercial property data in the United States.
The question that lingers as of mid-2026: whether the DOJ’s earlier antitrust action — now two decades old — was a skirmish in a longer war over how much control a private trade association should wield over the digital plumbing of America’s housing market. No new lawsuit has landed, but the technical and regulatory tensions that produced the 2005 case have not gone away.
