Prebid.org Clarifies Transaction ID Updates in Prebid.js

Written by: Garrett McGrath

Prebid.org today issued a statement to clarify recent updates related to Transaction IDs (TIDs) within Prebid.js, following industry discussion and some confusion around implementation timelines and adoption.

In June 2023, Prebid.js version 8 introduced support for TIDs, which were originally added to the OpenRTB specification in 2013. From the start, TIDs in Prebid have been opt-in, based on legal guidance and publisher feedback regarding data-sharing concerns. Publishers who wish to send TIDs must enable them manually — a policy that remains in place today.

Earlier this year, TIDs became a flashpoint in the programmatic ecosystem, with some DSPs requiring them as a condition for spend. To address this and promote flexibility across the market, the Prebid Publisher Committee voted in August 2025 to modify TID handling, making them SSP-specific rather than global. This decision reflected broad community consensus, not the actions of a small group of resellers as has been suggested publicly.

The update was implemented in Prebid.js version 10.9, following the release of version 10.0 in July 2025. Because many publishers take time to update major versions, the new TID logic currently represents approximately 1% of total Prebid traffic. The remaining 99% of TIDs continue to use the original global format.

To ensure flexibility and reduce confusion, Prebid.org will release an additional update this week allowing publishers using the latest version of Prebid.js (and who have opted to pass TIDs) to choose whether to send global or SSP-specific TIDs. All earlier versions of Prebid.js will remain unchanged, continuing to send a single global TID when enabled.

Prebid.org remains committed to transparency, interoperability, and publisher choice as it continues to support the open internet and strengthen collaboration across the advertising ecosystem.