When buying or selling properties in Arizona, one could get virtually nowhere without the Multiple Listing Service (MLS). The MLS is a database of homes for sale and an offer amongst brokers to compensate one another if they represent a buyer that purchases their listed property. It is the single best marketing tool available for sellers. For buyers, it is the single best means of finding homes. By hiring a real estate agent with MLS access or browsing MLS listings on a website, buyers can locate a multitude of purchase options without having to drive around all day looking for For Sale signs. Both buyers and sellers can use MLS sales data to identify similar sold properties (comps), an extremely useful step in deciding how to price a property or what to offer.

While the MLS is an extremely useful tool, how it is set up is a mystery to most homeowners. While MLS systems are typically set up as a separate corporation, each MLS is affiliated with local associations of Realtors. In some cases, multiple associations will combine to form or own their own an MLS. For instance, in Northwestern Arizona, three separate Mohave county-based Realtor associations, Bullhead City, Lake Havasu City, and Kingman, have combined their systems to form one system called WARDEX (Western Arizona Regional Data Exchange). In the Phoenix area, five separate associations share the same system called ARMLS (Arizona Regional Multiple Listing Service). » Read more: Arizona MLS Systems