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RESO’s Identifier Products Prepped to Make a Splash / Part 3 of 3, ULI

Providing identification is a basic aspect of moving about in the world, and we all have several IDs. In the real estate world alone, there are a series of identifiers to manage, including tax ID, agent license ID and the NRDS (National REALTOR® Database System) ID number assigned by the National Association of REALTORS® (NAR).*

RESO is building or upgrading three crucial IDs in order to simplify how you, your business and all the properties in the world operate within the real estate space.

The three identifiers in RESO’s wheelhouse include:

  • Universal Property Identifier (UPI)
  • Unique Organization Identifier (UOI)
  • Unique Licensee Identifier (ULI)

Identifiers are invaluable tools that can be used to track source data to a specific MLS for vendors, locate agents across multiple states and MLSs for associations, and manage properties across multiple MLSs without duplication.

We discussed the UPI in Part 1 of this series and the UOI in Part 2. We will now go over the ULI in Part 3.

Unique Licensee Identifier (ULI)

The ULI (Unique Licensee Identifier), formerly known as ULID, is a global single identifier for all licensed real estate practitioners that is in development.

The Research & Development Workgroup began the ULI Subgroup in November 2019, and the group has advanced the business case by leaps and bounds since that first meeting.

Over the last two years, the group has focused on identifying, exploring, and supporting core business needs, which are the successful de-duplication of licensee information and assignment of unique identifiers.

The ULI uses scoring and matching heuristics, which are probabilistic and consensus based. 

In order to match licensees across markets, the ULI relies on an aggregate member data pool so it can suggest potential matches outside of a given licensee data set. For example, a licensee record may have come from California but could represent an open license in Texas as well, creating the possibility of matches in that market.

Why It Matters
The activities of real estate sales licensees offer insights that guide businesses and consumers. The ULI will offer the ability to accurately track these activities across brokerages, association memberships or geographic boundaries, whether they are REALTORS® or non-REALTORS®, solving the limitations of the NAR NRDS/M1* number. The ULI will become the key to unifying marketwide industry data.

Going Forward
A matching algorithm has been proposed, and a proof of concept is being created to test it further. ULI mockups have also been created.

Data pilots covering multiple MLSs in the Pacific Northwest, New England and the Bay Area are being used to compare points of collision to resolve down to a single ULI to be used across all MLSs.

An API and user interface are in the works for the pilot project that will allow for participant data to be ingested and potential matches to be flagged for further review by MLS staff.

The goal is to create a prototype of the system and let the participants use it so we can collect statistics on matches, false positives and false negatives. 

A wealth of information about the ULI can now be found at

A white paper, containing both business and technical items, is underway and will be presented at the 2022 RESO Spring Conference.

RESO is of the mind that unique IDs, once codified into their best selves, will be used as happily as passports for island vacations, credit cards to buy stuff that gains miles for those vacations and the last four digits of your social for everything in between.

It’s the dawn of a new day for RESO ID standards, and your involvement will make the real estate industry run more efficiently than ever before.

Look for more information to be presented about the ULI at the 2022 RESO Spring Conference.

* Note: REALTORS® M1 or Members First, a new member engagement system, is being introduced by NAR this year to eventually replace NRDS.