MLS & Technology
IDX Information
Clear rules. Responsible marketing.
IDX (Internet Data Exchange) participation allows REALTORS® to display MLS listings on their websites in accordance with established rules and policies.
This page outlines IDX guidelines, compliance expectations, and participation requirements for UCARMLS members.
What is IDX?
Displaying MLS listings on your website
IDX — Internet Data Exchange — is the policy framework that allows MLS participants to display each other's listings on their own websites, mobile apps, and other digital platforms. It's the technology behind virtually every REALTOR® property search website.
Per the UCAR Bylaws (Article XVIII), UCARMLS is a facility for the orderly correlation and dissemination of listing information so participants may better serve their clients and the public. Through IDX, listings entered into UCARMLS can be displayed by other participating members — expanding the reach of every listing and giving consumers more ways to find properties online.
IDX participation is governed by NAR policy and UCARMLS rules, which UCAR adopts and enforces as part of its MLS operations. Use of information developed by or published by UCARMLS is strictly limited to the activities authorized under a participant's licensure — unauthorized uses are prohibited and may result in disciplinary action.
IDX at a glance
How IDX works
1. Listing entered into MLS — When you submit a listing to UCARMLS, it becomes part of the shared data feed available to IDX participants.
2. IDX feed distributed — UCARMLS provides an IDX data feed to participating members and approved vendors. UCARMLS must act on IDX feed requests within 5 business days.
3. Displayed on participant websites — Members who have opted into IDX can display listings on their personal or brokerage websites in accordance with NAR policy and MLS rules.
4. Updated regularly — IDX feeds are updated frequently to reflect current listing status, price changes, and new listings across the MLS.
Participation
Who can participate in UCARMLS IDX?
Per the UCAR Bylaws (Article XVIII), IDX participation is available to eligible UCARMLS participants who consent to the display of their listings by other participants. Here’s what you need to know.
Eligible Participants
Any REALTOR® of this or any other association who is a principal, partner, corporate officer, or branch office manager acting on behalf of a principal is eligible to participate in UCARMLS upon agreeing in writing to conform to the rules and regulations and paying the costs incidental thereto.
Broker License Required
No individual or firm is entitled to MLS participation unless they hold a current, valid real estate broker's license and offer or accept compensation to and from other participants, or are licensed/certified to engage in real estate appraisal. Mere possession of a broker's license is not sufficient — participants must actively endeavor to make or accept offers of cooperation and compensation on a continual and ongoing basis.
Subscribers
Subscribers include non-principal brokers, sales associates, and licensed and certified appraisers affiliated with participants. Subscribers also include affiliated unlicensed administrative and clerical staff and personal assistants under the direct supervision of an MLS participant or the participant’s licensed designee.
Approved Platforms
IDX listings may be displayed on websites, mobile apps, and audio devices under the participant’s control. All platforms must comply with the same display rules and requirements. Third-party IDX vendors must be approved and agree to comply with UCARMLS IDX rules before receiving a data feed.
Display requirements
What your IDX display must include
All IDX displays must comply with NAR policy and UCARMLS rules. The following are required elements for any IDX listing display.
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Listing Firm Identification
Every IDX display must identify the listing firm in a reasonably prominent location, in a readily visible color and typeface no smaller than the median used in the listing display. This requirement applies to both listing thumbnail views and full listing detail pages.
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Listing Broker Contact Information
The email or phone number provided by the listing participant must be displayed in a reasonably prominent location alongside the listing firm name. This ensures consumers can always contact the listing broker directly.
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Compliance with State Law
All electronic display of IDX information must comply with Tennessee state law and applicable regulations, in addition to NAR policy and UCARMLS rules. Members are responsible for ensuring their displays meet all applicable legal requirements.
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Separation of Non-IDX Listings
Listings obtained through IDX must be displayed separately from listings obtained from other sources. If displaying listings from multiple MLS IDX feeds, each must be consistent with the IDX rules of the respective MLS, and the participant must hold participatory rights in each MLS.
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Current & Accurate Data
IDX displays must reflect current listing information. Members are responsible for ensuring their IDX feed is kept up to date and that sold, expired, or withdrawn listings are not displayed as active.
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No Unauthorized Framing or Scraping
IDX data may not be used to populate any other database, reproduce listing information beyond what is authorized, or enable third parties to scrape or republish MLS data outside the scope of the IDX agreement.
Compliance guide
IDX do’s and don’ts
- ✓Display active MLS listings on your website, mobile app, or audio device
- ✓Co-mingle listings from multiple MLS IDX feeds in a single search (if you hold participatory rights in each MLS)
- ✓Use an approved third-party IDX vendor to power your property search
- ✓Display listing firm name and contact information alongside each listing
- ✓Link to full listing detail pages from search results
- ✓Use IDX to market your business and attract buyer and seller clients
- ✗Display listings without identifying the listing firm prominently
- ✗Use IDX data to populate a separate database or third-party platform outside the authorized scope
- ✗Display sold, expired, or withdrawn listings as active
- ✗Mix IDX listings with non-MLS listings without clearly separating the two sources
- ✗Allow unapproved vendors or third parties to access the IDX data feed
- ✗Display a seller’s listing via IDX if the seller has formally opted out of IDX display
Important notes
Seller opt-out & recent policy updates
Seller opt-out of IDX
Sellers have the right to request that their listing not be displayed via IDX. If a seller opts out, the listing must not appear on the internet or any other electronic display — including the listing firm’s own website.
Listing agents representing sellers who choose to delay public marketing must obtain a signed seller disclosure documenting the seller’s informed consent to waive the benefits of immediate public marketing through IDX and syndication. This applies to both delayed marketing exempt listings and office exclusive exempt listings.
2025–2026 MLS & IDX Policy Updates
UCAR adopts NAR MLS policy as part of its Bylaws (Article XVIII, Section 1). NAR approved significant updates in November 2025, effective January 2026. Key changes affecting IDX include:
- MLSs now have local discretion on whether to require association membership for IDX participation — this is no longer a national mandate. UCAR will communicate any local policy decisions to members.
- The Multiple Listing Options for Sellers policy (effective March 2025) created a new category of delayed marketing exempt listings — with required written seller disclosure documenting informed consent.
- Within one business day of publicly marketing a property, the listing must be submitted to UCARMLS for cooperation with other participants per the Clear Cooperation Policy.
- One-to-one broker-to-broker communications about listings do not trigger Clear Cooperation Policy requirements — but multi-brokerage communications do constitute public marketing.
- The UCARMLS Committee (7 REALTOR® members appointed by the UCAR President) oversees MLS operations and rules in accordance with UCAR Bylaws Article XVIII, subject to Board of Directors approval.
Questions about specific UCARMLS rules or policy changes? Contact UCAR staff.
Questions about IDX?
Need help with IDX setup or compliance?
UCAR staff can help with IDX feed requests, vendor approvals, and compliance questions. For the full NAR IDX policy, visit the NAR handbook directly.
Contact UCAR Staff → NAR IDX Policy →