TCF v2.3 Now Required for All Publishers and CMPs
All publishers and consent management platforms must use IAB Europe’s Transparency and Consent Framework v2.3. Non-compliant ad requests default to limited ads or get dropped entirely.
What Changed
IAB Europe Transparency and Consent Framework version 2.3 became mandatory for all publishers, advertisers, and Consent Management Platforms (CMPs) operating within Google’s advertising ecosystem as of March 1, 2026. Google officially dropped support for new TCF v2.2 consent strings on this date.
The most significant technical change is the introduction of a mandatory “disclosedVendors” segment in the TC string. This segment provides a binary indicator confirming whether each vendor was actually shown to the user in the CMP consent interface. Previous versions created ambiguity: vendors could claim Legitimate Interest without proof of disclosure.
Any ad request carrying a v2.2 string generated after March 1 defaults to “Limited Ads” mode or gets dropped entirely — directly impacting ad revenue. Publishers relying on Google Ad Manager, AdSense, or AdMob must ensure their CMP is Google-certified and supports TCF v2.3 signal generation.
Who's Affected
- Publishers using Google Ad Manager, AdSense, or AdMob in the EEA and UK
- Consent Management Platforms (CMPs) registered with the IAB Europe TCF
- Ad tech vendors participating in programmatic auctions via Google’s ecosystem
- Advertisers running display, video, and programmatic campaigns targeting EEA/UK audiences
Action Steps for Publishers & Advertisers
- 1Verify your CMP supports TCF v2.3 — contact your provider to confirm the mandatory disclosedVendors segment is deployed
- 2Audit your vendor list in the CMP UI — undisclosed vendors will have their bit set to 0, causing ad requests to fail
- 3Test TC string output using IAB’s TCF string decoder tools to verify proper v2.3 formatting
- 4Update OpenRTB integrations to pass the complete TC string including the new segment through the bid request chain
- 5Monitor ad revenue for drops after March 1 — increases in “Limited Ads” serving indicates non-compliant strings
- 6Coordinate with your legal/privacy team to ensure updated consent flows meet both TCF v2.3 and GDPR requirements
Key Dates
| Date | Milestone |
|---|---|
| Mid-2025 | Google begins accepting TCF v2.3 strings (transition period) |
| Feb 28, 2026 | IAB Europe deadline for all CMPs and publishers |
| Mar 1, 2026 | Google drops support for new TCF v2.2 strings — full enforcement |