Many brokers and agents are unaware that MLS rules prohibit advertising another broker’s listing on Internet websites like,, or any other third party website, without the listing brokers’ permission. While MLS rules do provide a framework that allows a broker to advertise other brokers; active listings on their own real estate brokerage website (MLS Rule 18 – IDX), this authorization is not extended to advertising listings on third party websites or advertising listings in printed materials, even if credit is given to the listing firm.

Advertising another broker’s listing is strictly limited to display on a brokerage website that is owned and operated by the broker advertising the property. Agents are also permitted to display other firms’ listings on their real estate websites in accordance with MLS IDX rules, specifically rule 18.3.4 which allows agents to display other firms’ listings by utilizing the free HAR provided IDX search solution, an authorized IDX provider, or by framing their broker’s public real estate website. If a broker or agent chooses to advertise another firm’s listings on their own real estate website, it is recommended they review all the  guidelines in MLS rule 18 that define how the listing content is to be displayed.

2.7 Advertising of Listing Filed with Multiple: Advertising of any listing by a Participant, other than the listing Participant, is permissible only with the consent of the listing Participant.

18.  IDX Defined (Internet Data Exchange): IDX affords MLS Participants (principal broker) the option of authorizing display of their listings on other participants’ Internet Web sites.

18.1 Authorization: Participants’ consent for display of their listings by other participants pursuant to these rules and regulations is presumed unless a participant affirmatively notifies the MLS that the participant refuses to permit display (either on a blanket or on a listing-by-listing basis). If a participant refuses on a blanket basis to permit the display of that participant’s listings, that participant may not download or frame the aggregated MLS data of other participants. Even where participants have given blanket authority for other participants to display their listings on IDX sites, such consent may be withdrawn on a listing-by-listing basis as instructed by the seller.

18.2 Participation: Participation in IDX is available to all MLS participants who are REALTORS® and who consent to display of their listings by other participants.

18.3.4 Non-principal brokers and sales licensees affiliated with IDX participants may display information available through IDX on their own websites subject to their participant’s consent and control and the requirements of state law and/or regulation by framing such information on (1) the association’s public access website, (2) through any MLS data licensee authorized to provide websites to Subscribers or (3) their Broker’s public access website with the permission of the Broker.

18.2.1 – 18.3.13 Provide guidelines to the operation of the IDX website and display of listing content.