The Council of MLS, an industry trade group that allows MLSs to collaborate on common initiatives and share best practices, released a new initiative today called SourceMLS. The goal of SourceMLS is to develop an industry-wide method that supports brokers with listing source validation. Listing validation allows brokers to take credit for having the best data quality of any consumer-facing website.

Listing data is widely distributed on the Internet today. Unfortunately, consumers do not have a way to know if the listing they are looking at is valid: really for sale, or if the listing information is accurate, or even if the website they are on is legitimate. The committee recognized the need to develop a brand stamp or mark that may be displayed on websites that meet the standards for listing display. The stamp is a SourceMLS badge. With widespread industry adoption of the SourceMLS badge on legitimate websites, consumers will learn to recognize which property search websites they can trust.


CMLS membership is open to any MLS. To participate in the program as a broker, your MLS must be a member of CMLS. Ask your MLS executive if they are a member of CMLS.

To display the badge as a broker or site owner, you must agree to the Guidelines and Trademark License Agreement. Here are the keynotes of the terms of use. Documents are linked below.

  • All listing information displayed comes directly from the MLS or an approved source. (like IDX)
  • The listing information is updated at least every twenty-four(24) hours. (like IDX)
  • The source of the listing information must be identified (like IDX)
  • The date and time the listing database was last updated must be displayed (Like most IDX)
  • The entire Source listing information is displayed without modification (like IDX)
  • The website on which the information is displayed is a CMLS approved site. (like IDX).

In effect, the SourceMLS initiative will act similarly to the way that the IDX disclaimer works today on your broker website. The principle difference is that your participation will play a role in supporting the industry with developing a professional real estate branded seal that consumers will grow to recognize and trust. Moreover, third party websites will not be able to display the seal unless they conform to the Terms of Use for participation.

For more information, please visit

View SourceMLS Listing Guidelines here 

View Trademark License Agreement here

WAV Group Partner Marilyn Wilson is on the Board of Directors for the Council of MLS. WAV Group Partner Victor Lund participated on the CMLS SourceMLS advisory committee.