Flat fee MLS (sometimes referred to as "flat rate mls" or "fixed fee mls") refers to the practice in the real estate industry of placing pertinent information about a property for sale into the database of the local Multiple Listing Service (MLS) for a set fee or dollar amount as opposed to a commission based on the sales price of the property.

In this instance, the listing contract between the real estate broker and the property owner typically requires the broker to enter the property into the MLS and calls for the seller to pay the broker a flat fee for the service. The net effect is to remove responsibility from the listing agency and make the real estate industry's standard MLS available as a marketing tool in exchange for a reduced cost.

This service is typically much differently than using a traditional real estate listing contract. The listing fee for a "flat fee MLS" can range anywhere from $200-$800 plus 2.5% to 3% for a "Buyer's Agent Commission", paid to a co-operating broker who brings a buyer. However, the commission which is normally paid to "listing" broker is replaced by payment of the flat fee. Depending on the area, while traditional brokers charge a total of 4% to 6% of the selling price of the property, that amount typically being split between two brokers involved in the transaction or two agents/brokers from the same company.