The two portals say the syndication agreement they struck last year provides advantages for both renters searching for homes and property managers looking to lease buildings.
Zillow and Redfin both asked a judge to toss out a lawsuit filed by the federal government that challenges an agreement between the two portals over a $100 million rental syndication deal they reached last year.
The agreement involves Zillow syndicating and serving as the exclusive source of multifamily rental listings on Redfin. In exchange, Redfin sends Zillow leads from renters.
The Federal Trade Commission filed a lawsuit in September seeking to permanently block the arrangement, calling it an “end run around competition.” Five state attorneys general filed a similar suit the next day, and the two cases were later consolidated into one.
Zillow and Redfin on Tuesday said that both cases failed to make an antitrust claim. In a separate filing made the same day, the companies said the partnership was pro-consumer.
“Over the last few years, Redfin struggled to grow its rental listings. Zillow, on the other hand, had a good supply of rental listings, but was always striving to provide a better platform for renters and deliver stronger performance to advertisers,” the companies wrote. “To address these issues, in February 2025, Zillow and Redfin announced a ‘Partnership’ centered on a syndication agreement.”
The companies said that providing more rental listings was a positive for renters searching for places to live and for apartment owners looking to lease out units.
“Property managers advertising with Zillow now automatically have access to a second listing service and thus more prospective renters who may generate leads,” the companies wrote. “By offering a more attractive package, the Partnership enables Zillow to compete more effectively with the many other firms that fight for property managers’ advertising dollars.”
One of those companies is CoStar, which owns Apartments.com and which views Zillow as a top competitor when it comes to both rentals and for-sale residential listings.
The FTC took issue with the fact that Zillow and Redfin were among the top three rental search platforms in the country, alongside CoStar. The commission said that the three competing portals accounted more than over 85 percent of online rental listing revenue last year.
The two portals questioned that figure in their filing.
“These allegations do not identify the combined shares for Zillow and Redfin — the two firms actually implicated by the Partnership,” the companies wrote. “Nor do they explain how the ‘rental listings’ or ‘revenues’ that underlie these figures were calculated.”
“Plaintiffs can only advance allegations of increased market concentration by lumping CoStar together with the Defendants — even though the Partnership enables both Zillow and Redfin to challenge CoStar’s dominance in the rental advertising industry,” the firms also stated.
The lawsuit is one of several challenging key segments of revenue for Zillow.
Zillow’s revenue from its rentals division rose 41 percent in the third quarter compared to the year before. The firm’s mortgage division revenue grew 36 percent. That’s compared to the company’s total revenue growth of 16 percent for the quarter.
Among other legal challenges, Zillow is also facing a lawsuit alleging the portal inflated costs to homebuyers through its Zillow Preferred referral program (formerly Zillow Flex), which imposes up to a 40 percent charge to agents who successfully close a transaction after receiving a lead generated on the platform.
The lawsuit was later expanded to focus on Zillow Preferred agents getting homebuyers preapproved with Zillow Home Loans.
Zillow addressed the various lawsuits in a video message to Zillow Preferred agents (formerly Zillow Flex) in December from Senior Vice President and General Manager of Zillow Preferred Zuhairah Washington.
“The claims in these lawsuits are false and fundamentally mischaracterize how Zillow Preferred operates,” Washington said in the video. “Everything we do starts and ends with the consumer. Buyers and sellers deserve choice in who they work with and transparency throughout the process. And that has been core to our model from day one.”
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