Brokers and their agents originate unique data—and that data fuels the technology systems and property information that every stakeholder in the real estate industry relies on. Multiple listing services amplify the data’s capabilities when they standardize it for use across broker tools, technology platforms and consumer-facing applications.
As the industry and technology advance, data standards must evolve—and MLSs are challenged to keep up with that change. The Real Estate Standards Organization, or RESO, is the authority when it comes to defining data standards in residential real estate and certifying compliance with those standards. By becoming RESO certified, MLSs ensure the language, practices, technology applications they use are up-to-date and uniform.
Leading and Lagging on Data Management
Many MLSs prioritize the critical job of keeping the data modernized and accessible. But not all do, and brokers are asking RESO: Why not?
Data standards are one of the rare industry investments that create a rising tide that lifts all boats. The National Association of REALTORS® funded RESO in its infancy and continues to be a major supporter, knowing that standards are a benefit to every broker and agent (particularly those working in more than one MLS area), MLS, association, technology partner and consumer. There’s a 27-year history documenting the development and success of standards in our industry.
The RESO Data Dictionary is the official list of data field names and definitions that create a universal technology language for MLSs. Today, 66% of the agents participating in U.S. MLSs are covered by a system with RESO’s most modern certification, Data Dictionary 2.0, and 80% are covered if we include the previous version, Data Dictionary 1.7.
That success requires us to also address the other side of the story because large MLSs with current certifications can obscure the gap in capability among other MLSs. In fact, a significant number of MLSs are not certified at all. And a large portion of certified MLSs are still on DD 1.7, introduced back in 2020. DD 2.0, introduced in April 2024, uses a certification framework roughly 10 times more rigorous, creating far more consistency and usability in the data that brokers rely upon.
These older certifications are keeping brokers’ data in a format that’s more than six years old. To put the technology transformation during that timeframe in perspective, DD 1.7 was created when Netflix was still mailing DVDs and AI in real estate was just the Zestimate.
Modernization Is a Management Priority
Brokers want better data management. They reach out to RESO to try to understand why the capability gap exists. And there are understandable reasons for some lagging certifications.
The MLS software providers, in some cases, are still working on meeting the standards, and MLSs may feel that they don’t have a role in that process. At RESO we understand particularly well that keeping up with the most current standards requires significant resources, focused work and coordination. But the reality of data providers being multiple years behind the current standard is a gap that brokers rightly recognize as something that the industry can no longer afford to leave unresolved.
There are other cases where modernization simply hasn't been given sufficient organizational priority by the MLS. Standardizing brokers’ data through RESO creates cost savings, streamlines product integrations, accelerates technology development, and unlocks access to new and innovative tools that would never scale across the industry without standards. Keeping brokers’ data current with modern RESO standards should be table stakes for MLS data stewardship.
AI Raises the Stakes
AI makes this need for consistent modernization even more urgent. In an AI-driven market, we shouldn't have every model invent its own interpretive map of what real estate data means and push it down on the industry. Our industry should provide the map. And we’ve already built that map together with you, through RESO’s standardized definitions and relationships.
But it won’t wield its maximum leverage or create its full impact until our industry partners are comprehensively using it in the data marketplace. The strongest way for our industry to establish authority over its data in an AI world is through deliberate business decisions: Standardize data and make its definitions powerful at scale, in public view.
Every gap in adoption reduces the value of the industry's collective data foundation. Each business will make this decision on its own, but its customers should understand the consequences and have their voices heard.
Time to Act
MLSs are powerful business cooperatives that create remarkable marketplace benefits for consumers and professionals. As stewards of brokers' data, their leaders face a fast-growing responsibility: Keep the data modern for all stakeholders’ needs today and strengthen its durability for the technology that will depend on it tomorrow.
If you’re a leader in your MLS, work with your technology provider. Put current certification on the priority list. Give brokers' data the modern foundation it deserves, and secure the authoritative position of brokers’ MLS data in the global technology marketplace.
Learn more about the benefits and process of RESO certification.
