A multiple listing service (MLS) is a private database of home listings that only licensed real estate professionals can access.
The MLS helps agents collaborate and helps buyers and sellers find each other. Most MLSs also have rules that help hold professionals accountable and enforce fair marketing practices.
When an agent posts a listing in an MLS, it gets syndicated or “pushed” to popular real estate sites. That's why you often see the same listings across websites.
In this article, we’ll talk about exactly what the MLS is, how it works, and why it matters.
If you’re ready to buy or sell and already know you want the full power of the MLS on your side, we’ll connect you with a top local agent who can help. Our network of vetted agents has access to your area’s MLS and the experience to use it effectively, helping you find the right home faster or get your listing in front of the most motivated buyers.
What is an MLS?
An MLS, or multiple listing service, is a private online database of real estate listings, only accessible to licensed real estate agents and other professionals who usually pay a fee for that access. The MLS is the main database for listings, and it's often critical for getting homes sold.
Here are some of the main things to know about MLSs:
- MLS listings are the gold standard in real estate. About 88% of sellers list their homes on the MLS, making it the number-one platform for home listings in the U.S.[1]
- Most of the listings you see on sites like Zillow are pulled from MLSs. When you sell your home with an agent, they’ll upload the listing to their MLS. Afterward, the listing will usually get pushed to the popular sites unless you opt out. But only some information gets shared. Other things remain private to professionals with MLS access, like certain documents or showing information.
- There are many reasons why the MLS is private. One is that it helps keep sellers’ information controlled and safe. For professionals, the MLS also has rules that promote oversight and accountability in marketing, helping to maintain a fair playing field.
- There are hundreds of MLSs, and professionals can only access the ones they subscribe to. If an agent wants information about a property listed in an MLS they are not subscribed to, they’ll have to call that listing agent directly. For this reason, some agents subscribe to multiple MLSs, even though it might cost them a little more.
How many MLSs are there?
There are over 500 MLSs across the U.S.[2] Each one is a separate database, usually covering different geographic areas, and they all work differently.
Most MLSs serve a defined region, such as a group of counties or a metro area. Agents who are members of that MLS can list properties and view full listing details (like showing instructions, disclosures, or other documents) within that system.
However, some areas — especially larger metros or regions near state lines — may be served by multiple MLSs. According to James Wang, founder and CEO of REAi, Inc., “It’s not uncommon for one city to be covered by more than one MLS.”
Even if two MLSs cover similar territory, they often operate differently. That’s because each one is typically run by different Realtor associations or groups, who set their own policies.
For example, one MLS may allow an agent to upload unlimited listing photos, while another caps it. Florida-based real estate agent Katerina Bucciarelli of Innovatiore Realty Group adds: “The technology platforms and user interfaces can vary. Listing input rules, field formats, and syndication practices may differ.”
In Indiana, the Indiana Regional MLS (IRMLS) serves around half of the state. Thirteen different Realtor associations manage it, with each representing a different region. However, this MLS does not cover Indianapolis or the cities around it.
Instead, Indy has its own MLS, called the Broker Listing Cooperative (BLC). It is managed by the Metropolitan Indianapolis Board of Realtors (MIBOR).
As an Indiana-licensed Realtor, I can help clients buy or sell statewide, but I subscribe to the IRMLS. If my client finds a house to buy in Indy, I’ll likely contact a BLC-subscribed agent for information on it.
Alternatively, if my client wants to sell in Indianapolis, I’ll have to post that listing to the IRMLS. But most agents who live and help buyers in Indy won’t see my listing, since their main MLS is the BLC. This can limit my seller’s exposure to that market.
For this reason, many agents in my area subscribe to both the IRMLS and the BLC. Others send clients to BLC-subscribed agents for better help.
This is just one example of how MLSs are used.
How does the MLS work?
The MLS is a platform real estate professionals use to list, market, and share detailed information about properties. When agents represent sellers, they upload everything from pricing and square footage to photos and showing instructions. This information is shared with other agents and syndicated to public sites like Zillow — but only partially.
Public listings often show fewer photos or less detail than what’s available inside the MLS. Agents and their clients rely on private MLS notes — like disclosures or seller preferences — to coordinate showings and negotiations. For buyers, the MLS is one of the most reliable tools for finding up-to-date listings and accessing key documents.
Listings on the MLS typically get pushed to sites like Zillow and Realtor.com, unless the seller opts out. But how those listings appear publicly can vary depending on the MLS's rules and tech. Some limit photo counts or listing fields, which means two similar homes could look very different online.
Each MLS is run locally and follows its own set of guidelines, which affects what data is required and how it's displayed. For example, one MLS in Indiana allows more photos than another, giving listings a more robust appearance. These differences don’t necessarily mean one MLS is better — just that sellers and agents have to adapt.
Technology also varies across MLS platforms. Some systems update listings across public sites almost instantly, while others lag due to outdated software. Because many MLSs are run by local Realtor associations with limited tech partners, innovation can be slow — and that can impact how competitive a listing is.
Efforts to standardize MLS technology and rules are ongoing, led by organizations like NAR and RESO, but progress is slow. For now, only licensed professionals can access the MLS directly. Sellers rely on their listing agent to get on the MLS, and buyers can work with their agents to get the full picture behind a property — one that public websites may not show.
What info does an MLS listing typically include?
MLS listings are designed to give real estate agents everything they need to market and sell a property. While some of that info shows up on public sites like Zillow, not all of it does.
Here’s what you’ll typically find both in the MLS and on a public site:
- Listing price
- Property address and location
- Square footage and lot size
- Number of bedrooms and bathrooms
- Photos and virtual tours
- Property descriptions
- Property type (single-family, condo, etc.)
- Year built
And here’s what is typically only available to those with MLS access:
- Showing instructions and scheduling tools
- Agent-only notes or remarks
- Documents like seller disclosures, surveys, and HOA guidelines
- Historical price changes and listing status updates
- Commission and brokerage details
This extra layer of information helps agents collaborate effectively and gives buyers and sellers an edge when making decisions.
What are the pros and cons of the MLS?
There are pros and cons for both buyers and sellers when it comes to the MLS. While it’s one of the most powerful tools in real estate, it’s not without its limitations, especially depending on the MLS used in your area. Getting the most out of it requires an agent who knows how to work with its quirks.
For buyers
Pros
- Access to accurate, real-time info. MLS listings are updated before the public sites, helping buyers avoid out-of-date listings or misinformation.
- More detailed search options. Agents can filter by nuanced features, like a home’s age, lot size, HOA restrictions, and more.
- Extra documents and insights. Disclosures, offer instructions, and agent-only notes give buyers deeper context to make stronger offers.
Cons
- The MLS can limit searching to specific regions. If a buyer is searching across multiple regions, their agent may only have access to the MLS covering one or two of them.
- Cross-MLS communication can cause delays. If a listing is in an MLS the buyer’s agent doesn’t belong to, they’ll need to reach out to the listing agent directly for details, which can slow down decisions or showings.
For sellers
Pros
- Credibility and trust. A listing on the MLS signals to other agents and buyers that the property is being marketed seriously and professionally.
- Exposure. MLS listings are seen by thousands of agents and syndicated to public sites, helping your home reach local buyers and people relocating from other areas.
- Built-in agent network. The MLS automatically alerts other agents when a new home hits the market, increasing the chances of fast showings and early offers.
Cons
- Not all MLSs are equal. Some MLSs limit how listings appear online, like restricting photo count or formatting options.
- Limited reach. While your listing will show up on public sites and be visible to everyone, details will be limited to agents who subscribe to the MLS your listing is posted in. They’ll have to contact the listing agent directly, which can cause delays.
- Slower updates in outdated systems. If your MLS has older tech, updates to your listing may take hours (or even days) to reach public platforms. Only other agents who subscribe to your MLS will get real-time updates.
Why is access to the MLS restricted to licensed real estate professionals?
There are a few reasons why the MLS is restricted to professionals. Here are the main ones:
- Accuracy and accountability. Only licensed agents and brokers can post and manage listings, which helps keep information accurate and up to date. They’re also held accountable by their local Realtor associations, usually the ones who manage the MLS.
- Privacy and security. The MLS holds sensitive information. This includes seller contact details, lockbox codes, and private remarks. Restricting access to the MLS keeps this information safe and protects everyone.
- Industry standards. MLS participation typically requires membership in a local Realtor association, which comes with a code of ethics and shared standards to protect buyers and sellers.
- Professional collaboration. It’s more than just marketing homes. The MLS also helps with showings, negotiations, and closing deals smoothly.
While buyers and sellers can still benefit from the MLS through their agent, direct access is limited in part to ensure it remains a trusted, professional-grade platform. As Alexi Morgado, founder of Lexawise Real Estate Exam Prep, puts it: “The MLS isn’t just a marketing tool. It’s a professional ecosystem built on trust, cooperation, and responsibility.”
Can I access the MLS if I don't have a Realtor?
There are a few ways to get MLS access without hiring a full-service real estate agent, whether you're buying or selling a home. Here's a quick overview of your options:
Sellers can use a flat fee MLS service. A flat fee MLS service lets you list your home on the local MLS without paying a full commission. Instead, you pay a one-time fee (usually a few hundred dollars) to a licensed broker who posts your listing. This gives your home the exposure it needs on both the MLS and public sites. Then you handle the rest of the sale yourself.
Buyers can browse public MLS data. Some MLSs allow limited public access through platforms like Nestfully. And most of the popular real estate sites pull MLS data to display listings. Just know that these sites may lag behind or leave out important info like showing notes, price changes, or offer deadlines.
The most complete way to access the MLS is by teaming up with a buyer’s agent. They can set up alerts, share private remarks, and help you move fast when a great home hits the market.
Each option has trade-offs, but MLS access can make a big difference, especially in competitive markets.
Do I have to use the MLS to sell or buy a home?
If you want to buy or sell a home without the MLS, there are limited options. Here are a few.
Selling a home without the MLS
Some sellers list their homes on platforms like:
- Zillow’s FSBO option
- FSBO sites like ForSaleByOwner.com or FSBO.com
- Facebook Marketplace or Craigslist
These tools let you advertise your home directly to buyers, often without paying an agent commission. However, agents with serious, qualified buyers using the MLS to find top-tier listings may miss yours.
Flat fee MLS listing services can bridge that gap, giving sellers access to the MLS for a set fee while handling the rest of the sale themselves.
Buying a home without the MLS
You can search for homes without MLS access using sites like Zillow, Redfin, and Realtor.com, which show most active listings pulled from MLS feeds.
But keep in mind, those public platforms don’t usually display everything, like private remarks or showing instructions. Also, sometimes listings update more slowly than on the MLS.
If you're working without a buyer’s agent, you can still contact listing agents directly when you're interested in a home using their contact information from public sites, or even yard signs.
History of the MLS
The earliest version of the MLS began in the late 1800s, when real estate brokers would gather in person to share information about homes for sale. These informal meetups were built on trust: if one broker found a buyer for another’s listing, they agreed to split the commission. That basic idea is still at the core of how the MLS works today.
The MLS was created because, as real estate became more competitive and more homes hit the market, brokers realized they needed a better way to organize and share listings. Over time, they built regional databases to collect and display home details in one place.
“The MLS allows agents and brokers to cooperate, providing broad visibility for properties and accurate, up-to-date information for buyers,” says Bucciarelli. This setup continues to help agents work together more efficiently.
Most of the more than 500 MLSs nationwide are run by local Realtor associations or real estate boards. Each one sets its own rules and membership fees, which is why the MLS experience can vary a lot depending on where you are.
From handshakes, to fax machines, to searchable online databases, the MLS has come a long way. But many real estate professionals would agree that the MLS is currently in a bit of a technological stagnation.
“Many MLSs still use old legacy software,” says Wang. This can slow down updates, cause glitches, and even leave certain systems open to security issues. The main culprit tends to be a limited number of tech companies working on MLS software, meaning they don’t have a lot of competition and thus aren’t pressed to innovate quite as fast yet.
To date, real estate advocacy organizations have begun solving the problem of how to streamline MLS rules and limitations, and also fund tech improvements. While progress tends to be slow due to the hundreds of Realtor associations running each separate MLS, the efforts continue.
Prior to 2024, listing agents could include in their MLS listings how much commission buyers’ agents would earn from the sale. (As a reminder, buyer agent commissions usually come from the seller, not the buyer.)
The point was to encourage more buyer activity — if the advertised commission looked good, then the buyer’s agent might be more motivated to show their client that property.
But in 2024, the National Association of Realtors (NAR) agreed to change how commission info is shared after a lawsuit claimed that its rules forced sellers to offer high commissions to buyer’s agents, even when they didn’t want to. Critics said this drove up home prices and limited choices for both buyers and sellers.
The result is that listing agents can no longer advertise how much commission a buyer’s agent will earn directly on the MLS. That info now has to be shared privately, which could make it harder for agents to know what to expect when writing offers.
Morgado says the MLS has to change with the times: “The MLS needs to modernize, not just technically, but in how it handles transparency, access, and agent collaboration.” Buyers are doing more research online, and sellers want better tools, so MLSs will need to keep up.
