Loss Notification

In OpenRTB, bidders can make use of bid loss notice/notification. Partners can include an endpoint (lurl) in their bid response that is called when losing the bid with additional information provided by the regarding exchange.

Reference: OpenRTB 2.5 Spec, Object: Bid, Attribute: lurl, Description:

Loss notice URL called by the exchange when a bid is known to have been lost. Substitution macros (Section 4.4) may be included. Exchange-specific policy may preclude support for loss notices or the disclosure of winning clearing prices resulting in ${AUCTION_PRICE} macros being removed (i.e., replaced with a zero-length string).

Supported Substitution Macros

Bidders can include the following macros in their lurl which are substituted with the regarding information when called.


Loss Reason Codes

The macro ${AUCTION_LOSS} provides a loss reason (ID). The following main loss reason codes are supported for an auction within our platform/marketplace.

Loss Reason ID

Loss Reason Code


Internal Error


Invalid Bid Response


Invalid Deal ID


Missing Markup


Missing Bid Price


Lost to Higher Bid


Lost to a Bid for a Deal


Buyer Seat Blocked


Creative Filtered – General; Reason Unknown


Creative Filtered – Disapproved by Exchange


Creative Filtered – Advertiser Exclusions


Creative Filtered – App Bundle Exclusions


Creative Filtered – Category Exclusions


Creative Filtered – Creative Attribute Exclusions

Minimum Bid To Win (Loss Price/Clearing Price)

The macro ${AUCTION_MINIMUM_BID_TO_WIN} provides insights on the minimum price needed to win the auction. Please mind, it is only set in case of loss reasons Lost to Higher Bid (102) and Lost to a Bid for a Deal (103).

Upstream Auction Signals

Our platform collects bid loss notification insights from upstream auctions for supported exchanges or integrations. Please get in touch with your account manager to get further details on the supported connections.

When applicable, this information is passed downstream to bidders on our platform when they win the auction within our marketplace, but eventually lose the upstream auction. Both loss reason and minimum bid to win (loss price) signals are passed.

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Last Modified: October 17, 2023 at 4:51 pm