How floors work in the Index auction

Media Owners
Last Updated: February 12, 2026•

A floor is a predefined minimum acceptable price for a winning bid for a piece of inventory. When floors are set on your inventory, Index Exchange will only accept bid responses from DSPs that are greater than or equal to the floor price, and reject bid responses below the specified floor price. Rejected bids that did not clear the floor price are shown as “bid below floor” in reports.

You can set floors in your ad server or in the Index UI.

Example

If a floor price is set to be $10, the following conditions apply:

  • A $10 bid from a DSP would be valid.

  • An $11 bid from a DSP would be valid

  • A $9 bid from a DSP would be considered invalid and classified as a bid below floor in reports.

Types of floors

There’s a few different types of floors that can be set at Index.

Request floor: A floor that is passed to Index in the imp.bidfloor field in the inbound bid request. For multi-format requests, this value could be passed in the format-specific banner.ext.bidfloor, video.ext.bidfloor, and native.ext.bidfloor fields within the imp object in the inbound bid request. Request floors are also referred to as upstream floors. For more information about these fields, see List of supported OpenRTB bid request fields for sellers.

Index UI floor: A floor that is configured in the Index UI that applies to open market demand. To learn how set a UI floor, see Set floors in the Index UI.

Deal floor: A floor that is configured in the Index UI that is associated with a Deal ID. To learn how to set a deal floor, see Create a direct deal.

Market floor: An optimized floor that Index calculates to be used with inventory that is missing a floor, or to optimize an inefficient floor price that already exists. For more information about Market Floors, see How Market Floor delivers more competitive bids through Index (Beta).

How Index decides which floor to send to DSPs

If there are multiple floor values applicable for a given request, Index determines which bidfloor value to pass to DSPs using the following process:

  1. Index receives a slot request from a publisher.

  2. Index retrieves the following floors that are valid for the auction for open market demand:

    • Request floor

    • Index UI floor(s)

    • Market Floor

  3. The floor types above are compared and one of the following occurs:

    • If the request only contains one format or you do not support multi-format requests, the highest floor price is added to the imp.bidfloor field in the bid request.

    • If it is a multi-format request and you support multi-format requests, the floor types above are compared for each format and the highest floor price specified for each format is added to the format-specific banner.ext.bidfloor, video.ext.bidfloor, and native.ext.bidfloor fields within the imp object in the bid request.

  4. If the bid request contains deal information, one of the following occurs:

    Deal typeFloor value
    If the deal is set to compete in the open market

    1. Index compares the following floors:

      • Request floor

      • Index UI floor(s)

      • Deal Floor

      • Market Floor

    2. The highest floor price from the list above is set as the pmp.deals.bidfloor value in the bid request we send to DSPs.

    If the deal is set as a private auctionIndex sends the original designated pmp.deals.bidfloor value in the bid request we send to DSPs.

How Index decides which floor to enforce during the auction

While ideally the floors that Index sends to DSPs are the same as the floors we enforce in our auction, the following floor types cannot be enforced until we receive a bid response back from a DSP:

  • Ad Unit (Specifically for multi-format and/or multi-size bid requests to DSPs.)

  • Advertiser Brand.

  • Industry

Index uses the following logic to determine which floor price is enforced during the Index auction:

  1. Index receives bid responses from DSPs.

  2. Index retrieves any additional floors associated with a bid response’s ad unit, advertiser brand, and industry.

  3. Index evaluates whether each bid clears these additional applicable floors.

  4. Bids that are lower than the highest floor price are rejected and classified as Bid Below Floor in reports.

  5. Bids greater than or equal to the highest floor price are considered valid and are passed on to the Index auction.

  6. Index performs the auction and returns the top bid(s) back to the Media Owner and classifies them as Bid Chosen in reports.