California's AB 325 makes algorithmic rent coordination among competing housing providers (landlords) an explicit violation of state antitrust law. If you use any pricing software that incorporates data from other landlords' properties to generate rent recommendations, you need to understand what this law prohibits and what it requires of you.
AB 325 joins a long list of new requirements - see our California landlord laws guide for the complete picture.
What Is AB 325?
Assembly Bill 325 is a 2026 California law that amends the Cartwright Act (Business and Professions Code 16720 et seq.) to explicitly prohibit algorithmic rent coordination among competing landlords. The bill was introduced in direct response to the federal Department of Justice investigation into RealPage, Inc., whose YieldStar software was alleged to facilitate price-fixing among competing apartment owners by pooling non-public rental rate data across participants.
How Algorithmic Rent Coordination Works
Algorithmic pricing tools collect rental rate and occupancy data from participating landlords, then use that pooled data to generate pricing recommendations. The legal problem:
- Competing landlords share non-public occupancy and rate data with a third-party algorithm
- The algorithm generates pricing recommendations based on pooled market data from all participants
- When multiple competing landlords follow the same algorithm's output, they effectively coordinate pricing without direct communication
Under federal antitrust law (Sherman Act) and now explicitly under California's Cartwright Act, this type of coordination is illegal regardless of whether the landlords ever spoke to each other directly.
What AB 325 Specifically Prohibits
AB 325 prohibits:
- Using an algorithmic pricing tool that incorporates non-public competitor rental rate data to generate pricing recommendations
- Sharing occupancy, vacancy, or rate data with a third-party pricing service that pools competitor data
- Following pricing recommendations from a service the landlord knows or has reason to know uses pooled competitor data
The law applies to individual landlords, property management companies using these tools on behalf of owners, and technology providers who facilitate the coordination.
What Is Not Prohibited
AB 325 is not a ban on software-assisted pricing. The following remain permitted:
- Using publicly available market data (Zillow, Apartments.com, local MLS data) to inform pricing decisions
- Using revenue management software that does not pool non-public competitor data
- Adjusting rent based on your own property's performance metrics
- Using third-party market analysis based on publicly available information to benchmark your rates
The distinction is between using public market intelligence (legal) versus participating in a system that pools private competitor data to generate coordinated pricing (now illegal under AB 325).
The Cartwright Act and What It Means for Landlords
The Cartwright Act is California's primary antitrust statute, equivalent to the federal Sherman Act. Before AB 325, it was unclear whether algorithmic coordination without an explicit agreement violated the Cartwright Act. AB 325 removes that ambiguity: algorithmic rent coordination is now an explicitly unlawful combination in restraint of trade.
Penalties under the Cartwright Act include:
- Civil damages, including treble damages for willful violations
- Attorney's fees for successful plaintiffs
- Injunctive relief
- Enforcement by the California Attorney General
Tenants can bring private actions under the Cartwright Act. A tenant who paid above-market rent due to an illegal coordination scheme can sue both the landlord and the pricing tool provider.
What Property Managers Need to Do Now
If you use any third-party pricing software, review whether it:
- Requires submission of your non-public occupancy or rate data as a condition of participation
- Generates recommendations based on pooled data from other participating properties in your market
- Discloses in its terms of service how data is aggregated across participants
If any of these apply, consult legal counsel before your next renewal. AB 325 is in effect as of 2026.
If you use AppFolio, Buildium, or similar platforms for operational tracking and make your own pricing decisions based on public market data, you are on sound legal ground.
The RealPage Context
The DOJ filed a civil antitrust lawsuit against RealPage in 2024, alleging that YieldStar facilitated price-fixing among multifamily landlords across dozens of U.S. markets. Several large institutional landlords were named as co-defendants.
Most individual landlords in Contra Costa County do not use institutional-grade tools like YieldStar. But the principles established by that case now apply broadly in California through AB 325. Any tool that pools competitor data and generates coordinated pricing recommendations is subject to the same legal analysis, regardless of vendor size or market share.
Frequently asked questions
What does AB 325 ban for California landlords?
AB 325 prohibits landlords from using algorithmic pricing software that incorporates competitor rent data to generate rent recommendations - a practice known as algorithmic rent coordination. The law targets platforms like RealPage that aggregated non-public rent data across multiple landlords to influence pricing across markets.
Can California landlords still use rental pricing software after AB 325?
Yes, with important limitations. Software that analyzes only your own historical data, publicly available listing data, or market-level indexes is not banned. What is prohibited is software that uses other landlords' non-public occupancy or rent data to coordinate pricing. Review your software vendor's data sourcing practices carefully.
What are the penalties for violating AB 325 in California?
AB 325 makes algorithmic rent coordination an explicit violation of the California Cartwright Act (state antitrust law). Violations can result in civil lawsuits, injunctions, and significant damages. The California Attorney General and private plaintiffs can both bring actions under the Cartwright Act.
Does AB 325 affect small landlords with one or two properties in California?
The law targets software and platforms used across multiple competing landlords rather than individual rent-setting decisions. Small landlords who set rent based on their own property data, publicly listed comparable rentals, or market reports are not affected. The risk is primarily for landlords using third-party pricing platforms with multi-landlord data pooling.
Sources
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