TCF v2.3 is open for public comment

Public comment period is open until May 19, 2025

IAB Tech Lab, in partnership with IAB Europe, continues to advance and enhance the Transparency and Consent Framework (TCF) to address the evolving expectations of users, regulators, and registered framework participants. This update will provide greater clarity for certain vendors on whether they have been disclosed to users in the scenario where this information isn’t clear from existing signals.

The TCF v2.3 technical specifications are now open for public comment through May 19th, 2025. Feedback can be submitted to support@iabtechlab.com. Outlined below are the technical changes included in TCF v2.3.

Vendor Disclosure Ambiguity

Vendors may face uncertainty in specific scenarios where it’s unclear whether they were disclosed to the user. This distinction is especially important when a vendor intends to process data for Special Purposes under Legitimate Interest. A previous update to the specification solved for the scenario where a vendor only declares Special Purpose(s). However, there was still ambiguity in the following scenario:

A vendor declares a legal basis of Legitimate Interest for one or both of the Special Purposes and only Legitimate Interest for Purposes.
The user exercises their “Right to Object” to the vendor’s processing based on Legitimate Interest. (Note: Special Purposes have only Legitimate Interest available as a legal basis and cannot be objected to via the Framework.)
The CMP will set the value to “0” which means Legitimate Interest not established or the user exercised their “Right to Object”
The vendor does not know if they were disclosed to the user and can therefore still pursue processing for the Special Purposes even though they cannot process for any of the Purposes.

Enhancements to the Vendor Disclosure Signaling

The technical specification already included a segment known as Disclosed Vendors, but it was previously optional and intended solely for use by CMPs – not included in the TC Strings shared with vendors. As its name implies, the Disclosed Vendors segment provides a binary signal indicating whether a vendor was disclosed to the end user: 1 = disclosed, 0 = not disclosed.

The Disclosed Vendors segment will be required in all TC Strings, where it must appear after the Core segment. The string may also include an optional Publisher Purposes Transparency and Consent segment.

[Core segment].[disclosedVendors segment].[Publisher TC]

Next Steps for TCF Participants

CMPs that already use the Disclosed Vendors segment will be required to update their implementations to ensure the segment is included in the TC String provided to vendors. Those not yet using the segment will need to implement it moving forward.

Vendors affected by the current ambiguity will be required to update their implementations to recognize and decode this new segment.

Key Dates to Keep in Mind

End of May – Finalization of the technical specifications
February 1st, 2026 (TBC) – All CMPs and Vendors will be required to update their implementation to support v2.3