Gov. Jared Polis on Thursday vetoed a measure that would have banned the use of many computer algorithms to set rent in Colorado, saying it could have outlawed some legitimate technologies used by landlords, and risked driving some housing providers out of the market.
Rent-setting algorithms have become a target of consumer protection advocates in recent years, who say software used by companies like RealPage effectively enables landlords to collude and drive up the cost of housing.
House Bill 1004 passed the legislature along party lines. A similar measure died at the Capitol last year.
In his veto letter, Polis said he agreed with the intent of the bill, writing that “collusion between landlords for purposes of artificially constraining rental supply and increasing costs on renters is wrong.”
But, he said, such practices are already illegal under Colorado’s Antitrust Act, and “violators should be held accountable” under existing law.
“We should not inadvertently take a tool off the table that could identify vacancies and provide consumers with meaningful data to help efficiently manage residential real estate to ensure people can access housing,” Polis wrote in the veto letter. “This bill may have unintended consequences of creating a hostile environment for providers of rental housing and could result in further diminished supply of rental housing based on inadequate data.
“The cost of rent is already too high,” he wrote.
The bill was sponsored by Rep. Javier Mabrey, a Denver Democrat, and emerged as a top priority of tenant and consumer protection advocates this session.
“This veto sends the devastating message that corporate landlords can keep using secret price-fixing algorithms to take extra rent from people who have the least,” Sam Gilman, co-founder of the Community Economic Defense Project, told The Colorado Sun in a statement. “Colorado families work hard for their wages and they deserve to keep them.”
A 2022 ProPublica investigation found that RealPage’s algorithm compiled rent data from competitors, then used that data to recommend rent increases to its customers.
In Denver, a 2024 study by the Biden White House found that algorithm-based price coordination by landlords increased rent by as much as $136 a month.
RealPage, whose software is used by some of Colorado’s largest landlords, denies that its service harms renters or violates antitrust laws.
In a statement, company officials applauded Polis for “doing the right thing” in vetoing the measure.
“This is the right outcome for all of us who desire a healthy housing ecosystem that benefits Colorado renters and housing providers alike,” Jennifer Bowcock, a RealPage spokesperson, told the Sun. “We want to thank Gov. Polis and the broad array of supporters of housing affordability who instead advocated for the responsible use of technology and tools like RealPage’s algorithmic pricing software to find fair pricing, ultimately benefiting all Coloradans.”
Colorado Attorney General Phil Weiser last year joined the U.S. Department of Justice and seven other states in suing RealPage over the practice, alleging that its software amounts to price-fixing in violation of federal antitrust laws.
The lawsuit quoted a landlord who described the product as “classic price-fixing” – the practice of market competitors coordinating to charge more, rather than competing for customers.
“It’s absolutely reasonable for landlords to use certain data to do business,” Deputy Attorney General Nathan Blake said at Colorado SunFest in May. “This is not just simply using what you can find on Zillow or Redfin – publicly available information about rental prices. It was sharing nonpublic, sensitive, competitive information across a whole sector, with the effect of colluding to raise prices in the rental market.”
House Bill 1004 was one of four bills Polis vetoed Thursday. That brings the number of bills passed by the legislature this year that he’s vetoed to 11 – breaking his single-year record of 10 set in 2023.
The other measures vetoed Thursday were:
More vetoes may be coming.
June 6 is the deadline for Polis to sign or veto bills passed during the 2025 legislative session. He can also let measures become law without his signature.
This story was updated at 9:30 a.m. Friday to include a statement from RealPage.