RESO Data Standards for IDX

by | Jun 9, 2021 | Real Estate News | 0 comments

RESO Announces “Broker Breakthrough” with New IDX Data Standards

April 2019
The Real Estate Standards Organization’s (RESO) newest update to its RESO Data Dictionary – version 1.7 – will add vital updates including a new IDX (Internet Data Exchange) requirement and Spanish Language capabilities. The RESO Data Dictionary is known as the real estate industry’s “Rosetta Stone” as it establishes a common language allowing real estate information to be understood and translated between systems. 

The New Data DictionaryThe new Data Dictionary 1.7 update includes an IDX data standard for Broker Reciprocity that has 219 fields related to the property. This new standard allows the same MLS property listing information from different MLSs to be delivered to brokers.

IDX is an essential tool for brokers as it enables them the right to display each other’s listings on websites and mobile apps. This move solves a common problem that occurs when brokers are members of more than one MLS. Because the IDX information that brokers currently receive is not standardized, brokers must spend time and resources to “normalize” the property information they collect from different MLSs before using it. The new requirement is expected to be applauded by the brokerage industry, which has pushed for IDX standardization.

“IDX standardization is now a reality,” said Art Carter, Chair of the RESO Board and CEO of California Regional MLS (CRMLS). “This has been a top priority for our Broker Advisory Group, and we are pleased to deliver a solution that the broker community has wanted to serve consumers better,” he added.

Exceptionally Good News

David Gumpper, who Chairs the RESO Broker Advisory Group, said, “This is exceptionally good news for brokers and for every IDX technology firm. It means quicker time to market and that brokers will be able to expand into new markets faster. If all MLSs follow NAR mandates, we will have the highest quality and consistency of IDX data going out across all markets. This gives consumers access consistently to the best information. Agents and brokers look better when the information we give consumers is better. We’ve been lobbying for an IDX standard for years, and now RESO is delivering a major breakthrough for brokers.”

Also, for the first time, the RESO Data Dictionary 1.7 update mandates that MLS organizations must implement the RESO Data Dictionary on the RESO Web API to obtain certification for the new version. This certification combines the validation of a company’s system to structure real estate information to RESO standards and the ability to communicate the information to others through an Application Programming Interface (API).

“The RESO Web API is the future for standardizing real estate data,” said Carter, “This will allow us to award MLSs RESO Data Dictionary and RESO Web API certifications instantly when the Data Dictionary is implemented on a certified RESO Web API platform,” he added.
Carter notes the RESO Data Dictionary is available to more than 1.3 million members of Multiple Listing Services (MLSs) nationwide – predominately real estate agents and brokers – mostly through a communication standard called RETS. Carter explains that RESO wants to see full MLS migration from RETS – a technology created in 1999 – to modernize how real estate information is communicated through current robust and responsive Web API technology.

In layman terms, the transition to APIs will mean that more real estate agents and brokers will gain access to the most current and accurate data available, thus delivering the right information to their consumers.

Growing Global Interest

The interest in RESO standards continues to grow globally. Firms in Canada and India are now using RESO standards, and interest is on the rise among international software development companies.  The RESO Data Dictionary, which now includes Spanish language fields, will serve Spanish speaking countries. Including Spanish also responds to requests from brokers and agents to better serve their sellers and buyers in the U.S. Fifty-two million people comprise the U.S. Hispanic and Latino population alone, according to the U.S. Census, and it’s growing at four times the rate of the nation’s total population.

Other updates for Data Dictionary 1.7 include the addition of hundreds of new data fields to provide for information on real estate agent teams, Open Houses, social media sites, roster information, property history, saved searches, showing events, and hundreds of pick list items related to property, members and offices.

Data Dictionary 1.7 also includes new fields for the RESO Organization Unique Identifier (OUID), a common method to give firms an identification number in the RESO ecosystem, as well as additional fields to track web user activity across the Internet.

“The latest version of the RESO Data Dictionary will deliver huge benefits to both real estate professionals and consumers,” said Rob Larson, Chair of the RESO Data Dictionary Workgroup and CIO of CRMLS.

A Living Document

An original pioneer of the Data Dictionary, which traces its roots to 2011, Larson added, “The dictionary is a living document and will continue to grow, but it’s exciting to reach this milestone. It’s taken the help of a lot of dedicated folks to get to where we are. But the implementation of this version by MLSs, brokerages, and software technology firms will lead to the improvement of websites, mobile apps, and other technologies, and we believe it will drive more innovation,” he added.

RESO’s commitment to evolve its Data Dictionary and real estate standards is shown by its dedication to hold conferences, which hosts its in-person Workshop meetings. Both Larson and Carter encourage brokers, MLSs, and technology firms to join them at the upcoming RESO Conference in Boise, Idaho, April 29-May 2, 2019. More improvements to the Data Dictionary and other RESO standards are part of the agenda.

About RESO

The mission of the Real Estate Standards Organization (RESO) is to create and promote the adoption and utilization of standards that drive efficiency throughout the real estate industry. RESO was incorporated in November 2011 as an independent, not-for-profit trade organization that was previously a section of the National Association of REALTORS®. RESO has some 850 active members, including NAR, multiple-listing services, real estate associations, brokerages and industry technology providers. For more information, visit Contact RESO via email at


Submit a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.