Zillow vs. REX: A Battle Over Fair Competition in Real Estate

The Ninth Circuit Court of Appeals is reviewing a case that could reshape the way real estate listings appear online. At the heart of the debate: Zillow’s 2021 policy change that separated MLS and non-MLS listings into separate tabs—an update that REX argues pushed them out of business.

Zillow says it was simply following industry rules. REX, however, claims this was an "anticompetitive scheme" that unfairly restricted non-MLS brokers from competing. So, was this a business decision, or was it a violation of antitrust laws?

The “No-Comingling” Rule: A Gray Area?

The case revolves around NAR’s no-comingling rule, which requires MLS and non-MLS listings to be displayed separately. While NAR argues this rule is optional, REX claims it was effectively mandatory—adopted by 71% of MLSs, forcing Zillow to comply or risk losing access to crucial listings.

One judge pressed REX’s attorney, asking if the real issue was Zillow’s website redesign rather than the rule itself. However, REX maintained that the policy change was the problem—not just its implementation.

Did Zillow and NAR Collude?

Zillow and NAR firmly denied working together. Zillow’s attorney argued that the no-comingling rule was simply an optional industry guideline, not a binding agreement between Zillow and NAR.

But the Department of Justice (DOJ) added a twist, stating that an "optional" rule can still act as an anticompetitive barrier if widely enforced. The DOJ asked the court to reconsider the case, suggesting the rule may have been a form of “concerted action” to suppress competition.

What This Means for Real Estate Professionals

If the court rules in REX’s favor, it could lead to major changes in how real estate platforms display listings, possibly making it easier for non-MLS brokerages to compete. On the flip side, if Zillow and NAR prevail, MLS-based rules will likely remain the industry standard.

For agents, this case highlights the ongoing battle between traditional real estate structures and emerging business models. Whether you’re an MLS participant or an independent broker, the outcome could impact how you market your listings online.

Bottomline

The verdict in this case could reshape how homes are listed and discovered online. As competition in real estate evolves, staying ahead of these changes is key. Whether you’re looking to buy, sell, or just navigate the shifting landscape, having the right expert in your corner makes all the difference. If you're thinking about making a move in Orange County, let’s connect—I’d love to help you find your way.

Reference: Anderson, T. (2025, February 17). Judges zero in on key question in REX’s appeal against Zillow, NAR. Inman.