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Internet Data Display (IDX) is a policy that allows brokers to exchange consent to display one another's property listings on the Internet. This program is known by several names, including Internet Data Display (IDD) and Broker Reciprocity, and several MLSs across the country have been doing it for years. But as of Jan. 1, 2002, NAR has mandated that all MLS must offer their participants a way to display the listings of other participants on their own Web sites. In other words, brokers can now post listing information directly from their local MLS on their own Web site without having to frame another other listing site -- with some limitations.


Do you have a website vendor that requires an IDX (RETS or WebAPI) feed to your website? Your IDX vendor needs to set up an account at If the IDX vendor has questions, have them email

Are you building your own website, and you are looking to generate an embeddable MLS property search, sometimes referred to as a framing link? Follow these step-by-step instructions for generating a framing link in Matrix: Click here You can also see examples of different search options on our Test IDX searches page: Click here


Please refer to Section 18 of the GIMLS rules and regulations for all IDX guidelines and best practices.


Careful consideration of the issues, technology, and rapidly evolving competitive online marketplace led the NAR Board of Directors to create this IDX policy that some have called the next evolutionary step for MLSs in the electronic age. Read the full policy here.


Q. How is Internet Data Exchange accomplished?

A. Other brokers' listings can be displayed either by downloading data from the MLS compilation and publishing it on your Web site or by framing the MLS's publicly accessible Web site (if such a site exists).

Q. Do I have to allow other Participants to display my listings on their Web sites?

A. No, Participants are free to withhold authority for such display - either on a blanket or on a listing-by-listing basis.

Q. What happens if I won't allow other Participants to display my listings on their Web sites?

A. If you prohibit the display of your listings by other Participants, you may not display their listings on your Web site pursuant to the IDX program. Other Participants may give you permission to display their listings but that permission would have to be sought and obtained separately from each Participant.

Q. What happens if a Participant doesn't blanketly prohibit other Participants from displaying her listings but instead indicates, each time she submits a new listing to the MLS, that her authorization to display that listing is being withheld. Since she hasn't issued a "blanket" prohibition against display by other Participants (but is constructively doing just that incrementally), is she entitled to display other Participant's listings?

A. No. A Participant cannot do indirectly what she cannot do directly. Since any Participant can opt out of IDX on a blanket basis, it can be presumed that those Participants who don't opt out are willing to allow other Participants to display their listings - except in those (likely) infrequent instances where a seller specifically prohibits the listing broker from allowing the listing to be displayed by other Participants.

This is analogous to the rules and policies of many MLSs that acknowledge the right of Participants to accept "office exclusive" listings in cases where a seller requests that their listing not be included in the MLS compilation.

Q. A Participant in our MLS has not blanketly prohibited display of his listings but over half of his new listings cannot be displayed by other Participants. Can we make a rule that a Participant cannot display other Participants' listings pursuant to the IDX program unless that Participant authorizes display of, say, 80% or 90% of their own listings?

A. No. But if a Participant doesn't opt out of IDX (by issuing a blanket prohibition of display by other Participants) he is presumed to be authorizing display of his listings by other Participants except in those instances where a seller specifically prohibits such display. If an inordinate number of listings cannot be displayed by other Participants, a rule could be established requiring listing brokers to certify that the benefits of having their property displayed on other Participants' sites had been explained to the seller but that the seller had refused to permit such display.

Q. If a Participant has blanketly prohibited display of her listings, can we require her to certify that she has explained the benefits of display by other Participants and the seller had nonetheless refused to allow such display?

A. No. If a Participant elects not to take advantage of IDX display, then they cannot be required to explain it's advantages to their clients. Such a rule would apply only to Participants who have opted into the program for those listings for which display is not authorized.

Q. If I don't participate in IDX but give another Participant permission to display my listings on their Web site, can the MLS (with my permission) transfer my listings to that Participant?

A. Yes. MLS may, but are not required to, transmit your listing information to any destination you authorize. The decisions as to whether an MLS will provide this service and whether to charge for such a service, are matters of local determination.

Q. If I want to authorize other Participants to display my listings under IDX, how do I do it?

A. Once your MLS implements the IDX program you don't need to do anything. The way the IDX program is structured, the consent of each Participant to permit display of their listings is assumed. If you choose not to permit display of your listings by other Participants, you simply notify the MLS that your consent is being withheld. It should be stated that some MLSs have chosen to use an "opt-in" approach to IDX under which Particpants must affirmatively signify their intent to participant in IDX. Determining whether to use an "opt-in" or "opt-out" approach is a matter of local option.

Q. Can the MLS refuse to accept my listings if I do not permit other Participants to display them on their Web sites?

A. No. Participants cannot be required to consent to display of their listings on other Participants' Web sites as a condition of participation in the MLS.

Q. Can the MLS refuse to transfer my listings to REALTOR.COM or to another aggregator of real property ads if I do not permit other Participants to display them on their Web sites?

A. Yes. Under the amended IDX policy, MLSs may, as a matter or local option, require participation in IDX as a condition of having listings transmitted to aggregators/publishers of real property ads.

Q. Does IDX conflict with license law or the Code of Ethics?

A. Implementation of IDX must be consistent with state law. NAR's IDX policy statement is consistent with the Code of Ethics since no display of other Participants' listings can occur without their consent. Consent, though, can be assumed unless affirmatively withheld by the listing Participant.

Q. Our MLS doesn't have a publicly-accessible Web site displaying Participants' listings. Does NAR's IDX policy mean we have to establish one so that Participants can frame each others' listings?

A. No. Framing is an IDX option available to Participants only if an association or MLS maintains a publicly-accessible Web site. NAR's policy does not require associations or MLSs to create such Web sites simply to provide this option to its Participants.

Q. Our MLS is computerized but is not Internet-based. Do we have to establish an Internet-based system to comply with NAR's IDX policy?

A. No, but under the IDX policy, by 2002 your MLS will have to permit Participants to extract listing information so that listing information can be displayed on other Participants' Web sites (unless, of course, consent is withheld by listing brokers).

Q. Can I authorize some, but not all, Participants to display my listings on the Internet?

A. If you consent to the display of your listings by other Participants under the IDX program, then any other Participant in the MLS may display your listings. If you prefer to authorize some, but not all, Participants to display your listings, this can be accomplished - though not under the IDX program. Separate consents would have to be granted to each Participant authorized to display your listings. As noted in an earlier question, MLSs may, but are not required, to transmit your listings to any destination you authorize. The decisions as to whether an MLS will provide such a service, and the related charges (if any) are matters to be determined locally.

Q. Can MLSs charge a fee for downloading listing information to Participants?

A. Yes, NAR's IDX policy does not affect the right of associations and MLSs to assess fees and charges for services provided to Participants. This remains a matter of local determination, subject to the parameters of existing policy (See Multiple Listing Policy Statements 7.9, 7.45, and 7.57 in the Handbook on Multiple Listing Policy).

Q. Does IDX mean that confidential information will now be available to the public?

A. No. IDX permits MLSs to prohibit display (by either downloading or by framing) of information intended exclusively for other real estate professionals and not for consumers.

Q. Must the listing firm be identified when I display other Participants' listings on my Web site?

A. This is a matter left to the discretion of local MLSs. Participants will want to keep the requirement of license law and the Code of Ethics (particularly Article 12) in mind when engaging in such displays.

Q. Can listing information be modified when it is displayed on other Participants' Web sites?

A. This, too, is a matter of local determination, although any authorized modification must comply with the "true picture" mandate of Article 12 of the Code of Ethics.

Q. Won't buyers (or individuals posing as buyers) be able to extract the entire MLS database and do whatever they want with it?

A. MLSs can, as a matter of local determination, establish reasonable limits on the amount of data and/or the number of listings consumers can retrieve in a particular query of Participants' Web sites.

Q. Won't IDX enable national and regional firms to aggregate listing information from many MLSs and create "super-MLSs"?

A. The ability to aggregate listing information from several MLSs remains subject to local MLS rules. Under IDX, MLSs may strictly limit the right to display other Participants' listings to those offices holding participatory rights in that MLS.

Q. Why should we let our listings be displayed on our competitors' Web site?

A. Letting other Participants display listings on the Internet is a business decision each Participant must make, taking into account their duty to promote the best interests of their clients; to cooperate with other REALTORS; and the opportunity to use the Internet to better serve their clients and customers.

(Note: These questions and answers are advisory in nature, have not been reviewed or approved by the Board of Directors of the National Association of REALTORS, and will be updated from time-to-time.)

Articles recently written about IDX (Broker Reciprocity) and more resources. More Resources for REALTORS®

The details in the resources below do not apply to every MLS since state laws and in some cases, association mandates, do differ. Contact your local association or MLS for its IDX regulations. REALTOR members do have the option to participate in their MLS's IDX program or not.

Broker Reciprocity & You: What you need to know about NAR's new policy, by Richard Westlund. From the California Association of REALTORS®' Real Estate Technology magazine. [11-01]

Broker Reciprocity Puts Traffic in Play: NAR policy good for brokers, bad for aggregators? From the California Association of REALTORS®' Real Estate Technology magazine. [7-01]

Brokers Take Control of Internet Leads: Systems help keep leads from falling through the cracks. From Realty Times. [11-01]

What is Internet Data Exchange. From REALTOR Association Executive magazine, Fall 2000.

Reciprocal Internet Listing Info from Regional MLS of Minn.

Broker Reciprocity, which was one of the models used by NAR to develop Internet Data Display, is actually the name of a branded term at the Regional MLS of Minnesota.

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