What Is an MLS?

What is an MLS? Who can use it? What information does it provide that a Zillow listing doesn't? You might already know the answers, but it never hurts to get a reminder of what an MLS is — and what it isn't — and how it works on Zillow.

What is an MLS?

MLS stands for multiple listing service. An MLS is a network for agents and brokers that grants them access to exchange property listing information and share compensation for a sale. There are more than 900 MLS systems in the United States, each with its own rules, regulations and database accessible only to its members. Individual MLSs are privately governed; they are not subject to state or federal supervision.

Real estate agents and brokers pay an annual fee to join an MLS, and they might belong to more than one, depending on how many MLSs there are in an agent's region. You do not need to join an MLS to be a real estate agent.

Wouldn't it be easier to have a single MLS?

Not necessarily. It would be rare for an agent in Phoenix, for example, to need access to a Seattle listing. And since that Phoenix agent pays a membership fee for his local MLS, he wouldn't want to get dinged for areas he doesn't access. Also, every state holds its real estate agents to different licensing regulations, so a single MLS would require standardized rules and compliance as well. Data integrity for MLS listings is pivotal, and addressing the thousands of violations that occur every year would bog down any MLS office. Logistically, a single national MLS just isn't realistic.

Who has access to an MLS?

Only licensed real estate agents can access an MLS, although some allow appraisers and assistants or office managers to join, even if they’re unlicensed. However, MLS listings are distributed to thousands of public websites including Zillow, which anyone can access.

What does an MLS listing have that a Zillow listing doesn't?

Certain confidential information — such as a homeowner’s contact information, the access code to a gated community, showing instructions or the amount of the agent’s commission — will not show up in Zillow listings.

Does Zillow use an MLS for its listings?

In part. Many MLSs are part of the Zillow Partnership Platform (ZPP), which was created by a direct relationship between Zillow and the originators (brokers) or keepers (MLSs) of the listing information. The common goal of the ZPP is to deliver and display accurate, curated and near real time listing data that serves both agents and consumers.

Now, MLSs can take advantage of the new Zillow Data Dashboard as part of the ZPP, a listing management and reporting platform that puts increased control in the hands of MLS members and brokers who send a direct feed to Zillow.

Why doesn't Zillow feature every MLS in the country?

We’re working on it! There are more than 900 MLSs in the United States and, understanding their significance and importance, Zillow would love to have each one as a partner. Direct listings are more accurate and timely, and create a better experience for consumers, MLSs and brokers.

Does Zillow use MLS listings to determine the Zestimate® home value?

No, the Zestimate — an estimated value of a home — is developed by complex data models designed by Zillow's economists, mathematicians, statisticians and computer scientists.

Everyone searching for their next home needs accurate, up-to-date real estate information, and MLS-based listings provide that. Since they’re subject to strict rules and compliance, MLS systems offer the best data available; it’s important to remember their purpose and power when explaining what an MLS is to clients.